OBJECTIVE Ovarian clear cell carcinoma (CCC) is associated with a poor prognosis and is resistant to chemotherapy. The aim of this study was to investigate the prognosis of CCC in Mie prefecture and to identify poor prognostic factors. METHODS In this multi-center retrospective study, we analyzed the data of patients with CCC between February 2012 and December 2020. Patients were staged according to the International Federation of Gynecology and Obstetrics (FIGO) 2014 system. Statistical analyses were performed using the Kaplan-Meier method and compared between the two groups using the log-rank test. RESULTS A total of 112 patients were included and the median follow-up time was 48 months. There was no difference in the prognosis between stages IA, IC1, and IC2. For patients at stages IA, IC1, and IC2, there was no difference in progression-free survival (PFS) and overall survival between the adjuvant chemotherapy and no chemotherapy groups. Median postrecurrent survival was 18 and 20 months in the stages I-II and III-IV groups, respectively. Multivariate analysis revealed that positive ascites cytology (p=0.006) was associated with PFS for patients at stages I-II and that the stage (p=0.039) was associated with PFS for patients at stages III-IV. CONCLUSIONS Positive ascites cytology was a poor prognostic factor for patients at an early stage of CCC. Postoperative chemotherapy could be omitted for patients in stages IA and IC1. Relapsed patients did not respond to the standard treatment and had a poor prognosis regardless of the primary stage.