Antitumor effect of MMC + UFT(A) and MMC + tegafur(B) therapies for advanced gastric carcinoma was compared from February 1985 to March 1988. UFT and tegafur were orally given at dose of 400 mg/m2 daily, and MMC was intravenously administered at dose of 6-8 mg/m2 every two weeks. The following results were obtained. 1. Twenty-nine cases entered in this study were divided into A or B therapies at random. All cases entered were eligible. Fourteen of 29 cases were randomized into A therapy and 15 cases into B therapy. One case treated with B was evaluated as incomplete. 2. There were no differences in the characteristics of patients between A and B therapies. 3. Among 29 eligible cases, a partial response was obtained in 3 out of 14 cases (21.4%) treated with A and in 3 out of 15 cases (20.0%) treated with B. Among 28 cases evaluated completely, a partial response was obtained in 3 out of 14 cases (21.4%) treated with each A and B. 4. Response rate with every ps or for every lesion did not differ between A and B therapies. 5. Median survival day treated with A and B therapies was 223 and 181 days, respectively. The survival curve did not differ significantly between the two therapies. 6. The frequency of adverse reactions within eight weeks after beginning the therapy was 64.2 and 73.3% with A and B therapies, respectively. From the results mentioned, it was concluded that the antitumor effect of UFT was not superior to that of tegafur for advanced gastric carcinoma.