Twenty-eight patients were treated with oral menogaril daily x 14 every 4 weeks. Granulocytopenia was dose-limiting at 50-60 mg/m2 per day. Neutropenic fever occurred in one patient. Thrombocytopenia occurred in 3 of 6 patients treated with menogaril 60 mg/m2/day. Nausea and vomiting and other toxic effects were generally mild. No cardiac toxicity was seen. One partial remission and three minor responses were noted among 11 previously treated patients with carcinoma of the bladder. One minor response was noted among 3 patients with colorectal cancer. The dose recommended for phase II studies is 50 mg/m2 per day for 14 days. Phase II studies are recommended in carcinoma of the bladder. Gastrointestinal toxicity is substantially less on this schedule than with oral menogaril administered on a weekly or q4wk schedule, but thrombocytopenia may be more common.