We report on a boy with ambiguous genitalia (hypospadias and cryptorchidism), a 46,XX/46,XY karyotype, complete Wolffian differentiation and no Mullerian derivatives, a left ovotestis, and no gonadal tissue on the right side. True hermaphroditism and regression of testicular tissue in this case indicate that chimerism may not only disturb gonadal differentiation but also arrest its development.191165168