OBJECTIVE The aim of this study is to evaluate the clinical characteristics of clear cell carcinoma of the ovary. METHODS Between 1986 and 1996, 45 patients with clear cell carcinoma of the ovary were identified by scanning the medical records department and the tumor registry at our institution. RESULTS Median age was 55 years (range 31-80 years). Tumors were 60% (27/45) stage I, 11% (5/45) stage II, 20% (9/45) stage III, and 9% (4/45) stage IV. All patients presented with a pelvic mass ranging in size from 2 x 3 to 20 x 30 cm and all except 1 had optimal cytoreduction. All patients received postoperative platinum-based chemotherapy, 47% (21/45) in combination with paclitaxel. One stage Ia patient refused therapy. Of the 6 stage III/IV patients with measurable residual tumor, 67% (4/6) partially responded to first line chemotherapy by CT scan or second look laparotomy. Recurrences occurred in 37% (10/27) stage I patients, including 18% (2/11) stage Ia, 33% (1/3) stage Ib, and 54% (7/13) stage Ic. Time to recurrence was 16 and 38 months for the two stage Ia patients and 35 months (median, range 18-56 months) for the stage Ic patients. Survival after recurrence was significantly related to disease-free interval after primary chemotherapy. With a median follow-up of 40 months (range 4-145 months), 93% (25/27) of stage I patients are alive, 20% (5/25) with disease, while 46% (6/13) of stage III/IV patients are alive. Median survival for the stage III/IV patients was 22 months (range 4-70 months). CONCLUSIONS Clear cell tumors of ovary frequently present at early stages. However, these tumors have a propensity for recurrence even after primary chemotherapy in early stage tumors.