Since the M-VAC (methotrexate, vinblastine, doxorubicin, cisplatin) regimen was reported by Sternberg in 1985, it has been widely accepted for the treatment of metastatic transitional cell carcinoma. This regimen has a significantly high response rate, but bone marrow suppression and gastrointestinal (GI) symptoms are inevitable. To complete this M-VAC regimen, preventive therapy for side effects is necessary. From November 1986 to March 1993, a total of 72 patients were admitted and received M-VAC therapy at our hospital. All of them had metastatic or invasive transitional cell carcinoma and they received a total of 163 complete courses of M-VAC therapy. We examined the side effects of this M-VAC regimen, and evaluated the effectiveness of colony-stimulating factor for prevention of granulocytopenia or granisetron for prevention of GI symptoms. Twenty-three patients (39 courses) were given recombinant colony-stimulating factor. This cytokine prevented the nadir of neutropenia and shortened the period to reach the nadir and period that the neutrophil count was below 1,000/mm3. Twelve patients (26 courses) were given granisetron, with significant reduction of the incidence of GI symptoms. These findings suggest that M-VAC therapy is effective and safe when used in combination with these drugs.