Four cases of primary transitional cell carcinoma (TCC) arising in the ovary (3 cases) and the parovarium (1 case) were collected for clinicopathologic analysis. The mean age was 46.2 years (range, 39-57 years). Two patients complained abdominal discomfort and vaginal discharge, respectively. Other 2 cases were incidentally found from routine check. Grossly, the tumors were solid and cystic (2 cases), solid (1 case) and surface papillary growth on capsule (1 case). Microscopically, the tumor showed almostly same to the histologic features of TCC of urinary bladder. Three cases were pure TCC, and one was mixed TCC and serous carcinoma. FIGO stage were 1 IIa, 2 IIc, and 1 IIIc. Treatment was surgery with adjuvant chemotherapy. Two patients are alive with no evidence of disease, and two have lung or brain metastasis.