A dose-finding study involving 27 untreated patients with ovarian cancer was performed to define the maximum tolerated dose of a 3-hour infusion of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) combined with a fixed dose of carboplatin. The median age of the study patients was 55 years (age range, 30 to 74 years), the median Eastern Cooperative Oncology Group performance status was 0 (range, 0 to 2), and residual tumor to first surgery was > or = 1 cm in 14 patients and less than 1 cm in 13 patients. All patients received carboplatin at a fixed dose of 300 mg/m2 over 1 hour. Paclitaxel was administered at five dose levels starting at 150 mg/m2 and increasing in 25-mg/m2 increments to 250 mg/m2. In the absence of toxicity, courses were repeated every 4 weeks for a total of six cycles. World Health Organization grade 1 hypersensitivity and cardiotoxicity were observed in 7.4% and 14.8% of patients, respectively. Moderate peripheral neuropathy was experienced by 29.6% of patients. Grades 3 and 4 neutropenia lasted less than 7 days; no patient required hospitalization for sepsis or febrile neutropenia, and no supportive treatment with granulocyte or granulocyte-macrophage colony-stimulating factor was needed. The maximum tolerated paclitaxel dose was not achieved.