SUPPLEMENT NO. 6 DATED JULY 16, 1997 TO PROSPECTUS DATED APRIL 29, 1996 RELATING TO 1,814,632 SHARES OF RENAL TREATMENT CENTERS, INC. COMMON STOCK, $.01 PAR VALUE All capitalized terms used but not defined herein shall have the meanings prescribed in the Prospectus dated April 29, 1996, as supplemented by Supplement No. 1 dated May 17, 1996, Supplement No. 2 dated December 11, 1996, Supplement No. 3 dated May 21, 1997, Supplement No. 4 dated June 5, 1997 and Supplement No. 5 dated June 27, 1997, forming a part of Form S-3 Registration Statement No. 333-3716. Donna R. and B.J. Matter, joint tenants with right of survivorship, Selling Stockholders, have transferred by gift an aggregate of 1,924 shares of Common Stock beneficially owned by them and covered by the Prospectus to the persons identified below, who are hereby added to the Prospectus as Selling Stockholders with respect to the shares set forth next to their names below. There is no relationship between any of these persons and the Company. Number Name of Shares John F. and Nancy Dahlin, joint tenants with right of survivorship 481 Kevin A. and Shelley Dahlin, joint tenants with right of survivorship 481 David Ray and Sandi Matter, joint tenants with right of survivorship 481 Melissa Ann Matter 481 The Dudley S.J. Seto Revocable Trust Dated 11/19/80, a Selling Stockholder, has transferred by gift 2,500 shares of Common Stock beneficially owned by it and covered by the Prospectus to the Iolani School. The Iolani School is hereby added to the Prospectus as a Selling Stockholder with respect to these 2,500 shares. There is no relationship between the Iolani School and the Company.