Familial male pseudohermaphroditism (MPH) due to 17,20-desmolase deficiency is rare. Here we present two siblings with MPH possibly due to 17,20-desmolase deficiency. The first patient presented with unambiguous female external genitalia and hypergonadotrophic hypogonadism. Chromosomal analysis revealed 46 XY. Ultrasound evaluation of pelvis revealed gonads in the inguinal canal, and no uterus. These findings were confirmed on laparotomy. Histology revealed the gonads to be testes. The second patient had ambiguous genitalia (perineoscrotal hypospadias, bifid scrotum with palpable gonads) with a 46 XY chromosomal pattern. Both patients had high plasma 17-hydroxy progestrone (17 OHP), low normal dehydro epiandrosterone sulphate (DHEAS) and low plasma testosterone. Plasma testosterone and DHEAS showed no response to ACTH or HCG. These features are compatible with the diagnosis of 17,20-desmolase deficiency.