Objective To detect 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1) expression in malignant epithelial ovarian tumors and analyze its relationship with pathological features and prognosis. Methods The clinical data of 70 patients with malignant epithelial ovarian tumors, 70 with borderline epithelial ovarian tumors, and 70 with benign epithelial ovarian tumors were retrospectively analyzed. Immunohistochemistry was used to detect 17β-HSD1 expression. The difference in 17β-HSD1 expression levels among three groups were compared, and the relationship between 17β-HSD1 expression and various clinicopathological features and prognosis was analyzed. Results Malignant epithelial ovarian tumor tissues had high 17β-HSD1 expression that was closely related to FIGO stage, lymph node metastasis, and carbohydrate antigen 125 (CA125) and human epididymis protein 4 (HE4) levels (P 0.05) . The 17β-HSD1 expression levels, preoperative CA125 and HE4 levels, tumor differentiation degree, and FIGO stage affected the prognosis of malignant epithelial ovarian tumors. Multivariate Cox regression analysis suggested that the 17β-HSD1 expression levels and FIGO stage were independent risk factors for malignant epithelial ovarian tumor. Conclusion Malignant epithelial ovarian tumors had high 17β-HSD1 expression, which is closely related to the occurrence and development of tumors and among the independent risk factors affecting the overall survival.