The aim of this study was to elucidate the clinicopathological and immunohisto chemical prognostic factors of patients with ovarian carcinosarcoma treated with radical surgery and postoperative chemotherapy. During a 6-year period, nine p atients with ovarian carcinosarcoma were referred to our institution. Tissue blo cks were reviewed and sections containing both carcinomatous and sarcomatous ele ments were stained for epithelial membrane antigen (EMA), vimentin, vascular end othelial growth factor (VEGF), CD45RO, c-erbB-2, p53, CD34, Ki67, S100, estrog en, and progesterone receptors. Histological and immunohistochemical findings as well as clinical characteristics were then correlated with progression-free in terval and overall survival. There were four homologous and five heterologous ca rcinosarcomas. Five patients had early stage disease. Seven of the patients were optimally debulked. All patients were treated with anthracycline-based chemoth erapy following surgery. With regard to immunohistochemistry, all specimens were negative for CD34, c-erbB-2, estrogen, and progesterone receptor expression. Five tumors overexpressed p53 and four specimens demonstrated a positive stainin g for Ki67. Reactivity for VEGF and CD45RO was observed in four and two tumor sp ecimens, respectively. The median overall survival was 32.9 months with no stati stical difference between early and advanced stages, while median time to progre ssion was 13.5 months. p53 overexpression demonstrated a trend for better overal l survival. Only p53 overexpression seems to influence overall survival although , due to the small number of patients studied, no safe conclusions can be drawn. Despite the predominance of early stage patients that favorably influenced over all survival, aggressive surgical cytoreduction followed by anthracycline-based treatment were the cornerstone in our multimodality approach. The aim of this study was to elucidate the clinicopathological and immunohisto chemical prognostic factors of patients with ovarian carcinosarcoma treated with radical surgery and postoperative chemotherapy. During a 6-year period, nine p atients with ovarian carcinosarcoma were referred to our institution. Tissue blo cks were reviewed and sections containing both carcinomatous and sarcomatous ele ments were stained for epithelial membrane antigen (EMA), vimentin, vascular endothelial growth factor (VEGF), CD45RO, c-erbB- 2, p53, CD34, Ki67, S100, estrog en , and progesterone receptors. Histological and immunohistochemical findings as well as clinical characteristics were then correlated with progression-free in terval and overall survival. There were four homologous and five heterologous ca rcinosarcomas. Five patients had early stage disease. Seven of the patients were optimally debulked. All patients were treated with anthracycline-based chemoth erapy following surgery. With regard t All tumors were negative for CD34, c-erbB-2, estrogen, and progesterone receptor expression. Five tumors overexpressed p53 and four specimens demonstrated a positive stainin g for Ki67. Reactivity for VEGF and CD45RO was observed in four and two tumors sp ecimens, respectively. The median overall survival was 32.9 months with no stati stical difference between early and advanced stages, while median time to progre ssion was 13.5 months. Only p53 overexpression seems to influence Despite the predominance of early stage patients that favorably influenced over all survival, aggressive surgical cytoreduction followed by anthracycline-based treatment were the cornerstone in our multimodality approach .