Abstract: Objective: Improve the knowledge of extraovarian Brenner tumor. Methods: One 68-year-old women with extraovarian Brenner tumor was presented. The Brenner tumor was malignant and found in retroperitoneal. With our case and privious reports, we discussed the clinical features, diagnosis, therapy and prognosis of extraovarian Brenner tumor. The pathology and histogenesis of extraovarian Brenner tumor were also analysed in the context of their unusual location and their origin. Conclusion: Because the diagnosis of extraovarian Brenner tumor is difficult before operation, our report is helpful to decrease clinical and pathological misdiagnosis.