A case of extrarenal Wilms' tumor presenting as an ovarian mass in a woman 56 years of age is described. Histologically, glomeruloid and tubular structures were identified within nests of undifferentiated epithelium. No teratomatous components were encountered. A review of the literature found three other reports of Wilms' tumor occurring in the female genital tract. This case represents the oldest patient with extrarenal Wilms' tumor in the literature.