OBJECTIVE The present study aimed to investigate the expression level of MicroRNA-25 (miR-25) in epithelial ovarian cancer (EOC) tissue, and examine its relationship with clinicopathological factors and prognosis of patients with EOC. METHODS Expression levels of miR-25 in 86 pairs of EOC tissue and adjacent normal tissue were measured by quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR). The comparison of the expression level of miR-25 between EOC tissue and adjacent normal tissue was performed using the two-sample Student's t test. The correlation between the expression of miR-25 and clinicopathological characters was assessed with the two-sample Student's t test. The overall survival was analyzed by log-rank test, and survival curves were plotted according to Kaplan-Meier. RESULTS The expression level of miR-25 in EOC tissue was significantly higher than in adjacent normal tissue. The miR-25 expression level was significantly positively correlated with tumor stage, histology, and regional lymph node involvement (P < 0.05). Kaplan-Meier analysis showed that patients with higher levels of miR-25 had significantly poorer survival than those with lower expression of this miRNA in patients, with a 6-year overall survival of 15.96 and 45.89 %, respectively, (P = 0.001). In the multivariate Cox proportional hazards analysis, high miR-25 expression was independently associated with poor survival (P = 0.002; HR = 2.119; 95 % CI = 1.568-3.221). CONCLUSIONS The increased expression of miR-25 is closely related to poor prognosis of EOC, indicating that miR-25 may serve as a predictive biomarker for the prognosis of EOC.