True hermaphrodites are extremely rare. The incidence of malignancies in cases of true hermaphrodites range between 1.9-2.6%, and is almost exclusively associated with cytogenetic mosaicism. All of the malignancies reported till date are germ cell neoplasms, namely, seminoma, gonadoblastoma or teratoma, mostly in the male phenotype. In this case we Illustrate a rare occurrence of a dysgerminoma of the ovary, its treatment and responses, in a 35-year-old true hermaphrodite with a female phenotype, and cytogenetic mosaicism.