Twenty-seven patients with advanced ovarian cancer were treated with a total of 80 courses of cis-dichlorodiammine platinum (II) (cisplatin). The doses in three courses were less than 50 mg/m2, in 64 courses they were 50 mg/m2, and in eight courses they were 100 mg/m2. In addition, five courses of low-dose daily treatment (20 mg/m2 for five days) were administered. Twelve patients received cisplatin alone, 12 received cisplatin and cyclophosphamide (750 mg/m2), and three patients received cisplatin with other drugs. There were eight responders (33%) in the 24 evaluable patients. Renal toxicity occurred in four patients, ototoxicity in four, and leucopenia (which was life-threatening in one patient) occurred in 16 patients (white cell count less than 3.0 X 10(9)/L). There were two early drug-related deaths. The median survival of patients who responded to cisplatin treatment was longer than 30 weeks compared with nine weeks for non-responders.