Purpose.:Ovarian clear-cell carcinomas (OCCC) are known to be possibly resistant to platinum-based chemo- therapy and to have a poorer prognosis with respect to other subtypes of epithelial ovarian cancer (EOC). This study was undertaken to compare response and survival to platinum-based chemotherapy between patients with advanced stage III and IV OCCC and serous EOC (sEOC). Patients and methods.:A retrospective analysis was performed in patients with advanced stage of OCCC treated with first-line platinum-based chemotherapy in the context of several study protocols of the Hellenic Cooperative Oncology Group (HeCOG) between 1/2/1987 and 31/10/2003. The outcome was compared to that of patients with sEOC treated according to the same protocols during the same study period. Results.:One hundred and five patients (35 stage III and IV OCCC,70 stage III and IV sEOC) treated with platinum-based chemotherapy were analyzed. The overall response rate for OCCC was 45%(complete response 25%) (95%CI,23.1%to 68.5%) and 81%(complete response 46%) (95%CI,67.4%to 91.1%) for sEOC. The overall response rate was significantly higher for sEOC (P = 0.008). In the subgroup of stage III patients,the rate of complete responders was higher among sEOC patients (P = 0.023). After a median follow-up of 61.1 months,median survival and time to tumor progression were not significantly different between the two groups (25.1 months 95%CI 11.7 to 38.5 months versus 49.1months 95%CI 36.5 to 61.6 months ,P = 0.141,12.0 months 95%CI 6.5 to 17.3 months versus 18.0 months 95%CI 14.7 to 21.6 months ,P = 0.384,respectively). Conclusion.:Patients with OCCC have significantly lower response to platinum-based first-line chemotherapy compared to patients with sEOC. This low response to platinum-based chemotherapy was not translated in significantly shorter survival. The current study outcomes are provocative and suggest that a new strategy for chemotherapy in OCCC should be adopted,possibly one that focuses on new agents without cross-resis- tance to platinum agents. Purpose .:Varian clear-cell carcinomas (OCCC) are known to be possibly resistant to platinum-based chemo-therapy and to have a poorer prognosis with respect to other subtypes of epithelial ovarian cancer (EOC). This study was undertaken to compare response and survival to platinum-based chemotherapy between patients with advanced stage III and IV OCCC and serous EOC (sEOC). Patients and methods.: A retrospective analysis was performed in patients with advanced stage of OCCC treated with first-line platinum-based chemotherapy in the context of several study protocols of the Hellenic Cooperative Oncology Group (HeCOG) between 1/2/1987 and 31/10/2003. The outcome was compared to that of patients with sEOC treated according to the same protocols during the same study period. The overall response rate for OCCC was 45% (complete response 25%) (95% confidence interval) C (95% CI, 67.4% to 91.1%) for sEOC. The overall response rate was significantly higher for sEOC (P = 0.008). In the subgroup of stage III patients, the rate of complete responders was higher among sEOC patients (P = 0.023). After a median follow-up of 61.1 months, median survival and time to tumor progression were not significant different between the two groups (25.1 months 95% CI 11.7 to 38.5 months versus 49.1 months 95% CI 36.5 to 61.6 months, P = 0.141, 12.0 months 95% CI 6.5 to 17.3 months versus 18.0 months 95% CI 14.7 to 21.6 months, P = 0.384, respectively) Conclusion: Patients with OCCC have significantly lower response to platinum-based first-line chemotherapy compared to patients with sEOC. This low response to platinum-based chemotherapy was not significantly in survival. The current study outcomes are provocative and suggest that a new strategy for chemotherapy in OCCC should be adopted, possibly one that focuses onnew agents without cross-resistance to platinum agents.