EXHIBIT 5.1 ALSTON & BIRD LLP One Atlantic Center 1201 West Peachtree Street Atlanta, Georgia 30309-3424 404-881-7000 Fax: 404-881-4777 www.alston.com December 21, 2004 Renal Care Group, Inc. and the Subsidiary Guarantors listed on Annex A 2525 West End Avenue, Suite 600 Nashville, Tennessee 37203 Re: Registration Statement on Form S-3 Ladies and Gentlemen: We have acted as counsel to Renal Care Group, Inc., a Delaware corporation (the "Company"), and the subsidiaries of the Company listed on Annex A hereto (the "Subsidiary Guarantors" and together with the Company, the "RCG Entities"), in connection with the Company's registration statement on Form S-3 (the "Registration Statement") filed with the Securities and Exchange Commission (the "Commission") under the Securities Act of 1933, as amended (the "Securities Act") on September 24, 2004, relating to the registration of $160,000,000 aggregate principal amount of the Company's 9% Senior Subordinated Notes due 2011 (the "Notes") and related guarantees by the Subsidiary Guarantors of the Notes (the "Guarantees" and together with the Notes, the "Securities") pursuant to (i) the Indenture, dated as of October 22, 2003 (including any supplemental indenture, the "Indenture") by and among the Company, as successor to National Nephrology Associates, Inc. ("NNA"), the Subsidiary Guarantors named therein and Wells Fargo Bank, N.A., as successor in interest to Wells Fargo Bank Minnesota, N.A., as trustee (the "Trustee"), (ii) the First Supplemental Indenture, dated as of April 2, 2004, by and among the Company, the Subsidiary Guarantors named therein and the Trustee, (iii) the Second Supplemental Indenture, dated as of April 30, 2004 by and among the Company, the Subsidiary Guarantors named therein and the Trustee, and (iv) the Registration Rights Agreement dated October 22, 2003 by and among the Company, as successor to NNA, the Subsidiary Guarantors named therein and Banc of America Securities LLC, J.P. Morgan Securities Inc., RBC Dominion Securities Corporation, and Harris Nesbitt Corp. (the "Registration Rights Agreement"). This opinion is furnished at your request to enable you to fulfill the requirements of Item 601(b)(5) of Regulation S-K, 17 C.F.R. Section 229.601(b)(5) in connection with the Registration Statement. <Table> Bank of America Plaza 90 Park Avenue 3201 Beechleaf Court, Suite 600 601 Pennsylvania Avenue, N.W. 101 South Tryon Street, Suite 4000 New York, NY 10016 Raleigh, NC 27604-1062 North Building, 10th Floor Charlotte, NC 28280-4000 212-210-9400 919-862-2200 Washington, DC 20004-2601 704-444-1000 Fax: 212-210-9444 Fax: 919-862-2260 202-756-3300 Fax: 704-444-1111 Fax: 202-756-3333 </Table> Renal Care Group, Inc. and Subsidiary Guarantors December 21, 2004 Page 2 The Guarantees are set forth in Article Eleven of the Indenture and a notation of the Guarantees is endorsed on each Note or otherwise deemed to be delivered therewith under the terms of the Indenture. The Indenture is subject to and governed by the Trust Indenture Act of 1939, as amended (the "TIA"). We have examined the forms of the Securities, the Indenture, the Registration Rights Agreement, the Registration Statement, including the amended Statement of Eligibility under the TIA of the Trustee filed as an exhibit thereto, and such documents, records, certificates and other instruments as we have deemed necessary or advisable for the purposes of rendering the opinions hereafter set forth. We also have made such further legal and factual examinations and investigations as we deemed necessary for purposes of expressing the opinions set forth herein. As to certain factual matters relevant to this opinion letter, we have relied conclusively upon originals or copies, certified or otherwise identified to our satisfaction, of such records, agreements, documents and instruments, including certificates or comparable documents of officers of the RCG Entities and certificates of public officials, as we have deemed appropriate as a basis for the opinions hereinafter set forth. Except to the extent expressly set forth herein, we have made no independent investigations with regard to matters of fact, and, accordingly, we do not express any opinion as to matters of fact that might have been disclosed by independent verification. We have assumed, without any independent verification, (i) the genuineness of all signatures, (ii) the legal capacity of all natural persons, (iii) the authenticity of all documents submitted to us as originals, (iv) the conformity to the original documents of all documents submitted to us as conformed, facsimile, photostatic or electronic copies, (v) that the forms of the Securities conform to those included in the Indenture, (vi) based upon recent certificates of the Secretaries of State or similar government officials of the State of Delaware or other jurisdictions indicated on Annex A (or recent informal confirmations of Corporation Service Company or its affiliates), that each of the RCG Entities is a corporation, limited partnership or limited liability company, validly existing under the laws of its jurisdiction of incorporation or formation, (vii) that all parties other than the Company to the documents examined by us have the requisite corporate, partnership or limited liability company power and authority under the laws of their respective jurisdictions of incorporation or formation to execute, deliver and perform their obligations under such documents and under the other documents required or permitted to be delivered and performed thereunder, and (viii) the due authorization, execution and delivery of the Indenture and the Securities by the Subsidiary Guarantors other than corporations organized under the laws of the States of Delaware and Georgia, as indicated on Annex A, under the laws of their respective jurisdictions of incorporation or formation. We have also assumed that the Indenture has been duly authorized, executed and delivered by the Trustee, and constitutes the valid and binding obligation of the Trustee, enforceable against the Trustee in accordance with its terms, and that the Trustee is, with respect to acting as a trustee under the Indenture, in compliance with all applicable laws and regulations. Renal Care Group, Inc. and Subsidiary Guarantors December 21, 2004 Page 3 This opinion is limited in all respect to the federal laws of the United States of America, the laws of the State of New York, the laws of the State of Georgia, and the Delaware General Corporation Law (together with applicable provisions of the Constitution of the State of Delaware and reported judicial interpretations thereof). We express no opinion herein as to any other laws, rules or regulations. Based upon and subject to the foregoing, and subject to the other assumptions, qualifications, limitations and exceptions set forth herein, we are of the opinion that: 1. The Notes, when duly authenticated by the Trustee and issued and delivered in accordance with the provisions of the Indenture, constitute valid and legally binding obligations of the Company, enforceable against the Company in accordance with their terms, except as the enforcement thereof may be limited by bankruptcy, insolvency (including, without limitation, all laws relating to fraudulent transfers), reorganization, moratorium or other similar laws affecting creditors' rights generally, and except as the enforcement thereof is subject to general principles of equity (regardless of whether enforcement is considered in a proceeding in equity or at law). 2. The Guarantees constitute valid and legally binding obligations of the Subsidiary Guarantors, enforceable against the Subsidiary Guarantors in accordance with their terms, except as the enforcement thereof may be limited by bankruptcy, insolvency (including, without limitation, all laws relating to fraudulent transfers), reorganization, moratorium or other similar laws affecting creditors' rights generally, and except as the enforcement thereof is subject to general principles of equity (regardless of whether enforcement is considered in a proceeding in equity or at law). This opinion letter is provided for use solely in connection with the transactions contemplated by the Registration Statement and may not be used, circulated, quoted or otherwise relied upon for any other purpose without our express written consent. Our opinions herein are limited to those matters set forth in Opinion Paragraphs 1 and 2 above, and no opinion may be implied or inferred beyond the opinions expressly stated. This opinion letter is effective as of the date hereof and we hereby expressly disclaim any obligation to supplement the opinions expressed herein for any changes which may occur hereafter with respect to any matters of fact or law addressed herein. Renal Care Group, Inc. and Subsidiary Guarantors December 21, 2004 Page 4 We consent to the filing of this opinion letter as an exhibit to the Registration Statement and to the use of our firm's name under the heading "Legal Matters" in the Prospectus constituting a part thereof. In giving such consent, we do not thereby admit that we are within the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations of the Commission thereunder. Very truly yours, ALSTON & BIRD LLP By /s/ Paul M. Cushing --------------------------------- Paul M. Cushing A Partner ANNEX A <Table> <Caption> ENTITY STATE OF INCORPORATION OR FORMATION - ------ ----------------------------------- NNA of Oklahoma, Inc. Nevada NNA of Georgia, Inc. Delaware NNA of Alabama, Inc. Alabama NNA Management Company of Kentucky, Inc. Kentucky National Nephrology Associates Management Company of Texas, Inc. Texas NNA of Nevada, Inc. Nevada National Nephrology Associates Credit Corporation Tennessee NNA of Toledo, Inc. Ohio NNA of Rhode Island, Inc. Rhode Island NNA Properties of New Jersey, Inc. New Jersey NNA Management Company of Louisiana, Inc. Louisiana Renex Corp. Florida Renex Management Services, Inc. Florida Dialysis Services of Atlanta, Inc. Georgia Renex Dialysis Clinic of Penn Hills, Inc. Pennsylvania Renex Dialysis Clinic of Shaler, Inc. Pennsylvania Renex Dialysis Clinic of Doylestown, Inc. Pennsylvania Renex Dialysis Clinic of Amesbury, Inc. Massachusetts Renex Dialysis Clinic of North Andover, Inc. Massachusetts Renex Dialysis Clinic of South Georgia, Inc. Georgia Renex Dialysis Clinic of Creve Couer, Inc. Missouri Renex Dialysis Clinic of St. Louis, Inc. Missouri </Table> <Table> <Caption> ENTITY STATE OF INCORPORATION OR FORMATION - ------ ----------------------------------- Renex Dialysis Clinic of Bridgeton, Inc. Missouri Renex Dialysis Clinic of Union, Inc. Missouri Renex Dialysis Homecare of Greater St. Louis, Inc. Missouri Renex Dialysis Clinic of Maplewood, Inc. Missouri Renex Dialysis Clinic of University City, Inc. Missouri Renex Dialysis Facilities, Inc. Mississippi Renex Dialysis Clinic of Bloomfield, Inc. New Jersey Renex Dialysis Clinic of Orange, Inc. New Jersey Renex Dialysis Clinic of Philadelphia, Inc. Pennsylvania Renex Dialysis Clinic of Pittsburgh, Inc. Pennsylvania Renex Dialysis Clinic of Woodbury, Inc. New Jersey Renex Dialysis Clinic of Tampa, Inc. Florida Dialysis Associates, LLC Tennessee Dialysis Associates Medical Supply, LLC Tennessee NNA-Saint Barnabas, L.L.C. New Jersey NNA Saint Barnabas - Livingston, L.L.C. New Jersey NNA of Oklahoma, L.L.C. Oklahoma NNA of Louisiana, LLC Louisiana Doylestown Acute Renal Services, L.L.C. Pennsylvania NNA of Newark, L.L.C. New Jersey National Nephrology Associates of Texas, L.P. Texas NNA Properties of Tennessee, Inc. Tennessee NNA Transportation Services Corporation Tennessee Renal Care Group East, Inc. Pennsylvania </Table> ii <Table> <Caption> ENTITY STATE OF INCORPORATION OR FORMATION - ------ ----------------------------------- Renal Care Group Michigan, Inc. Delaware Kentucky Renal Care Group, LLC Delaware Michigan Home Dialysis Center, Inc. Michigan Renal Care Group of the Midwest, Inc. Kansas Four State Regional Dialysis Center, Inc. Missouri Fort Scott Regional Dialysis Center, Inc. Missouri Miami Regional Dialysis Center, Inc. Missouri RCG Mississippi, Inc. Delaware Renal Care Group of the Southeast, Inc. Florida Northeast Alabama Kidney Clinic, Inc. Alabama Renal Care Group Texas, Inc. Texas Dialysis Management Corporation Texas RCG PA Merger Corp. Texas STAT Dialysis Corporation Delaware Angleton Dialysis, Inc. Texas Brazoria Kidney Center, Inc. Texas Fondren Dialysis Clinic, Inc. Texas Wharton Dialysis, Inc. Texas Jefferson County Dialysis, Inc. Arkansas KDCO, Inc. Missouri Lawton Dialysis Inc. Arkansas Little Rock Dialysis, Inc. Arkansas Northwest Dialysis, Inc. Arkansas RenaLab, Inc. Delaware RCG Finance, Inc. Delaware </Table> iii <Table> <Caption> ENTITY STATE OF INCORPORATION OR FORMATION - ------ ----------------------------------- RenalPartners, Inc. Delaware RenalNet, Inc. Delaware Diabetes Care Group, Inc. Delaware Renal Care Group Arizona, Inc. Arizona Renal Care Group Northwest, Inc. Delaware RenalNet Arizona, Inc. Arizona RCG University Division, Inc. Tennessee R.C.G. Supply Company Tennessee Renal Care Group Alaska, Inc. Alaska Renal Care Group Southwest Holdings, Inc. Delaware Dialysis Centers of America - Illinois, Inc. Illinois SSKG, Inc. Illinois Renal Care Group Ohio, Inc. Delaware Physicians Dialysis Company, Inc. Pennsylvania Dialysis Licensing Corp. Delaware RCGIH, Inc. Delaware Renal Care Group Southwest, L.P. Delaware Arizona Renal Investments, LLC Delaware RCG Indiana, L.L.C. Delaware Stuttgart Dialysis, LLC Arkansas RCG West Health Supply, L.L.C. Arizona Renal Care Group Texas, LP Delaware Wound Care Group, Inc. Delaware Renal Care Group Westlake, LLC Delaware </Table> iv