A randomized clinical study of patients with advanced epithelial ovarian cancer after debulking surgery showed that high-dose (120 mg/m2) cis-platinum (DDP) in combination with cyclophosphamide (600 mg/m2) had a significantly higher response and survival rate than the low-dose DDP (60 mg/m2) and cyclophosphamide combination. The 3-year actuarial survival rate of the high-dose group was 60% and that of the low-dose group was 30%. Though moderate to severe marrow toxicity was evident in 80% of the patients in the high-dose group and 40% of the low-dose group, no serious sepsis or death developed as a result of the marrow depression. Mild neurotoxicity was observed in 55% of the patients in the high-dose group and only 20% in the low-dose group. Mild nephrotoxicity was seen in 25 and 17% of patients in the high- and low-dose groups, respectively. It was concluded that the 120 mg/m2 dose DDP and cyclophosphamide combination should be used in the treatment of carcinoma of the ovary in spite of its toxicities. However, it should only be used in institutions with supportive facilities in the management of patients with severe marrow depression.