Pure-type clear cell carcinoma (CCC) has been recognized as a distinct subtype of ovarian cancer, showing a resistance to chemotherapy and resulting in poor prognosis. Our aim was to evaluate the effects of complete surgical procedures followed by adjuvant chemotherapy for CCC patients whose tumors were confined to the ovary (pT1M0). During the period of 1987-2005, 56 patients with stage I CCC were identified and two cases were excluded due to retroperitoneal lymph node metastasis. A total of 54 patients were enrolled in the study and divided into two groups: Group A (n=38, 1993-2005) underwent complete surgical staging including pelvic and para-aortic lymphadenectomy. Group B (n=16, 1987-1992) underwent a hysterectomy, bilateral salpingo-oopherectomy, omentectomy without comprehensive lymphadenectomy. Every patient received six courses of adjuvant chemotherapy using a platinum agent. Survival analysis was estimated by the Kaplan-Meier method and prognostic factors were evaluated using a Cox regression model. The clinical characteristics of the two groups were similar, except for the rate of conventional platinum-based chemotherapy (p=0.02). Multiple regression survival analysis revealed that the completion of a comprehensive staging operation was the only independent factor for progression-free survival of stage I CCC patients (p=0.03) and that the chemotherapeutic regimen was not a prognostic factor (p=0.43). The present study indicates that we should accomplish complete surgical staging procedures for CCC confined to the ovary.