Cisplatin (Platinol) has an important dose-response relationship in ovarian cancer. We have used high-dose cisplatin (40 mg/m2q d X 5) administered in 250 mL 3% saline and 6 L/d of saline hydration in a phase II trial in refractory ovarian cancer patients and together with cyclophosphamide (Cytoxan) (200 mg/m2 qd X 5) in previously untreated advanced ovarian cancer patients. High-dose cisplatin produced a 32% response rate in the phase II trial with a median survival of 12 months for all patients entered in the study and 16 months for responding patients. In previously untreated patients, the preliminary results indicate that intensive treatment with high-dose cisplatin and cyclophosphamide of short duration (3 to 4 months) can produce a high complete remission rate (60%). The dose-limiting toxicity of high-dose cisplatin has been peripheral neuropathy, which limits the number of cycles of high-dose cisplatin that can be administered. Alternative ways to administer higher doses of cisplatin include the use of sodium thiosulfate as a protective agent and the intraperitoneal administration of cisplatin in ovarian cancer patients. These results demonstrate that the cisplatin dose is an important factor in achieving improved results in the treatment of ovarian cancer.