[HALE AND DORR LETTERHEAD APPEARS HERE]     
 
                                                                   May 22, 1998
 
United Natural Foods, Inc.
260 Lake Road
Dayville, CT 06241
 
Re: Registration Statement on Form S-3
 
Ladies and Gentlemen:
 
  This opinion is furnished to you in connection with a 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"), for the registration of an aggregate of
4,887,500 shares of Common Stock, $.01 par value per share (the "Shares"), of
United Natural Foods, Inc., a Delaware corporation (the "Company"), of which
(i) 1,001,270 Shares will be issued and sold by the Company and (ii) the
remaining 3,886,230 Shares will be sold by certain stockholders of the Company
(the "Selling Stockholders") (including 637,500 Shares issuable upon exercise
of an over-allotment option granted by the Selling Stockholders) .
 
  The Shares are to be sold by the Company and the Selling Stockholders
pursuant to an underwriting agreement (the "Underwriting Agreement") to be
entered into by and among the Company, the Selling Stockholders and Donaldson,
Lufkin & Jenrette Securities Corporation, Smith Barney Inc. and Wheat First
Union, as representatives of the several underwriters named in the
Underwriting Agreement, the form of which has been filed as Exhibit 1 to the
Registration Statement.
 
  We are acting as counsel for the Company in connection with the sale by the
Company and the Selling Stockholders of the Shares. We have examined signed
copies of the Registration Statement as filed with the Commission. We have
also examined and relied upon the Underwriting Agreement, minutes of meetings
of the stockholders and the Board of Directors of the Company as provided to
us by the Company, record books of the Company as provided to us by the
Company, the Certificate of Incorporation and By-Laws of the Company, each as
restated and/or amended to date, and such other documents as we have deemed
necessary for purposes of rendering the opinions hereinafter set forth.
 
  In our examination of the foregoing documents, we have assumed the
genuineness of all signatures, the authenticity of all documents submitted to
us as originals, the conformity to original documents of all documents
submitted to us as copies, the authenticity of the originals of such latter
documents and the legal competence of all signatories to such documents.
 
  Our opinion in clause (ii) below, insofar as it relates to the Selling
Stockholders' shares being fully paid, is based solely on a certificate of the
Chief Financial Officer of the Company.
 
  We assume that the appropriate action will be taken, prior to the offer and
sale of the Shares in accordance with the Underwriting Agreement, to register
and qualify the Shares for sale under all applicable state securities or "blue
sky" laws.

 
  We express no opinion herein as to the laws of any state or jurisdiction
other than the state laws of the Commonwealth of Massachusetts, the Delaware
General Corporation Law statute and the federal laws of the United States of
America. To the extent that any other laws govern the matters as to which we
are opining herein, we have assumed that such laws are identical to the state
laws of the Commonwealth of Massachusetts, and we are expressing no opinion
herein as to whether such assumption is reasonable or correct.
 
  Based upon and subject to the foregoing, we are of the opinion that (i) the
Shares to be issued and sold by the Company have been duly authorized for
issuance and, when such Shares are issued and paid for in accordance with the
terms and conditions of the Underwriting Agreement, such Shares will be
validly issued, fully paid and nonassessable and (ii) the Shares to be sold by
the Selling Stockholders have been duly authorized and are validly issued,
fully paid and nonassessable.
 
  It is understood that this opinion is to be used only in connection with the
offer and sale of the Shares while the Registration Statement is in effect.
 
  Please note that we are opining only as to the matters expressly set forth
herein, and no opinion should be inferred as to any other matters. This
opinion is based upon currently existing statutes, rules, regulations and
judicial decisions, and we disclaim any obligation to advise you of any change
in any of these sources of law or subsequent legal or factual developments
which might affect any matters or opinions set forth herein.
 
  We hereby consent to the filing of this opinion with the Commission as an
exhibit to the Registration Statement in accordance with the requirements of
Item 601(b)(5) of Regulation S-K under the Securities Act and to the use of
our name therein and in the related Prospectus under the caption "Legal
Matters." In giving such consent, we do not hereby admit that we are in the
category of persons whose consent is required under Section 7 of the
Securities Act or the rules and regulations of the Commission.
 
                                          Very truly yours,
                                             
                                          /s/ Hale and Dorr LLP     
                                          -------------------------------------
                                          HALE AND DORR LLP
 
 
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