Many new treatments for peptic ulcer continue to appear in the literature. Some of these treatments are discarded after a brief period. Inevaluating the results of any treatment in peptic ulcer, caution must be exercised, because some ulcers heal spontaneously or with little treatment. Interest has been stimulated by Co Tui and his associates1in the treatment of peptic ulcer with protein hydrolysate. They reported favorably on the use of protein hydrolysate in 30 patients with peptic ulcer. Hodges2reported favorably on 26 patients and Kimble3reported favorably on 14 out of the 15 patients with peptic ulcer treated with protein hydrolysate. The purpose of this study is to evaluate the effectiveness of the oral administration of protein hydrolysate in the treatment of peptic ulcer. Co Tui1stated that there is a protein deficiency in a large number of patients with peptic ulcer. We were unable