Clusterin has been found to be overexpressed in several human malignancies and also be expressed in ovarian carcinoma tissues. However, to date, no study has investigated the prognostic significance of clusterin expression in ovarian carcinoma. Therefore, we examined the relationship between clusterin overexpression and clinicopathological features to determine its prognostic relevance. Eighty-six patients diagnosed with primary ovarian cancer between 1993 and 2004 were selected and recorded follow-up data and clinicopathological data. The expression of clusterin was detected on the sections of tissue microarray by immunohistochemistry and was evaluated the association with patient's clinical features and prognosis. Overexpression of clusterin protein in ovarian cancer was observed in 46.5% of the patients and was found more often in disease that was in the advanced stage (P = 0.0001). The expression levels of clusterin was associated with International Federation of Gynecology and Obstetrics stage (P = 0.0001) and histologic type (P = 0.002). However, no significant association was observed between clusterin expression and patient age or tumor Silverberg grade (P > 0.05). In addition, the average survival time of the patients with clusterin overexpression was significantly shorter than that with normal expression of clusterin. Clusterin expression was associated with survival of patients with primary ovarian cancer (relative risk for overall survival 1.69; 95% confidence interval, 1.52 to 1.95 (P = 0.033)). Our data show that clusterin is not only a biomarker associated with ovarian cancer, but it also appears to be a prognostic factor associated with adverse outcome.