Ovotesticular disorder of sex development is historically thought to confer a relatively low risk of germ cell malignancy relative to other disorders of sex development. This is likely due in part to the high prevalence of a normal 46,XX karyotype in these patients. However, disorders of sex development represent a broad phenotypic spectrum, and often patients cannot be neatly categorized with a single diagnosis. We report an atypical case of ovotesticular disorder of sex development in a child with ambiguous genitalia and 45,X/46,XY mosaic karyotype. Prophylactic bilateral gonadectomy was performed at age 14 months.