The combination of paclitaxel 135 mg/m2 (24-hour infusion) and cisplatin 75 mg/m2 is now considered the standard treatment in first-line chemotherapy for stage III suboptimally debulked and stage IV ovarian cancer. Interest is focused on the possibility of evaluating the combination of paclitaxel with carboplatin, because it was found to be less nefrotoxic and less neurotoxic than cisplatin. This study seeks to determine the maximum tolerated dose and to assess the antitumor activity of the combination of a 3-hour paclitaxel infusion followed by carboplatin. Thirty-three chemotherapy-naive patients with stage III-IV epithelial ovarian cancer entered this open, nonrandomized dose-finding study. The first dose level investigated was paclitaxel 125 mg/m2 and carboplatin 250 mg/m2: the dose level progression was performed by alternatively increasing paclitaxel 25 mg/m2 and carboplatin 50 mg/m2. Cycles were repeated every 28 days. At least three patients were treated at each dose level. Overall, 233 and 224 cycles, respectively, are evaluable for nonhematologic and hematologic toxicity. Dose-limiting toxicities (febrile neutropenia and severe fatigue) were observed in two of six patients at level VIII (paclitaxel 225 mg/m2 and carboplatin 400 mg/m2) and therefore the previous dose-level (paclitaxel 200 mg/m2 and carboplatin 400 mg/m2) was considered as the maximum tolerated dose. Neutropenia (grade 3-4 in 63% of cycles), neurotoxicity (grade 2 in 37.5% and grade 3 in 9% of patients), arthromyalgias (grade 2 in 53% of patients and grade 3 in 3% of patients), and grade 3 alopecia were the most common toxicities observed. The incidence of thrombocytopenia was low (grade 3 in 4% of cycles) and no renal toxicity was observed. An objective remission was documented in 74% of 31 evaluated patients, including eight complete remissions (26%) confirmed by second-look surgery. The combination of paclitaxel 200 mg/m2 3-hour infusion followed by carboplatin 400 mg/m2 (30-minute infusion) is a safe and active regimen as first-line chemotherapy for advanced ovarian cancer.