Objectives To evaluate tumour response rate and toxicities of gemcitabine and carboplatin in chemonaive subjects with advanced epithelial ovarian cancer. Design A phase II study. Setting Gynaecologic oncologic unit. Population Twenty chemonaive International Federation of Gynecology and Obstetrics (FIGO) stage IIIc and stage IV subjects with ovarian cancer. Main outcome measures Tumour response, disease free and overall survival and toxicity. Methods Intravenous gemcitabine 1000 mg/m(2) on day 1 and day 8 and carboplatin at area under centre (AUC) = 5 on day 1 were administered three weekly for six cycles. Subjects who received more than three cycles of chemotherapy were eligible for assessment of turnout response, while all the cycles of chemotherapy were assessed for toxicities. Results The mean age of the subjects was 57.3 years, and the median follow up was 38.7 months. Of the 18 eligible subjects analysed, 11 (61.1%) showed a complete clinical response, and the overall response rate was 83.3% (15/18). The median overall survival was 29.2 [95% (confidence interval) CI 22.8-35.6] months, and the median progression-free survival was 11.6 (95% Cl 4.7-18.5) months. WHO grade 3 anaemia, neutropenia and thrombocytopenia was 7.6, 9.5 and 0%, respectively, on day 8, and 15.5, 12.2 and 15.5%, respectively, on day 15. Two subjects required a total of three hospital admissions for neutropenic sepsis, and two required five hospital admissions for platelet transfusion for severe thrombocytopenia. Conclusion Chemonaive advanced ovarian cancer showed a high response rate to combined gemcitabine and carboplatin chemotherapy. The subjects developed moderate adverse reactions. Phase III study to evaluate the role of combined gemcitabine and carboplatin as first-line chemotherapy in ovarian cancer is warranted.