We report on two genotypic females with complete masculinization of the external genitalia secondary to congenital adrenal hyperplasia resulting from 21-hydroxylase deficiency. One patient had the salt-losing variant, and the other had the simple virilizing or nonsalt-losing variant. One was evaluated neonatally during an adrenal crisis and misidentified as male; the second was unrecognized. Both were being reared as males when the true genotype was recognized during evaluation for cryptorchidism. The female internal genitalia were subsequently removed and testicular implants placed. These cases demonstrate the need to exclude congenital virilizing adrenal hyperplasia in any phenotypic male infant with bilateral cryptorchidism. When this condition is diagnosed, early and genotypically appropriate sex assignment is important if reproductive function is to be preserved and subsequent emotional and social complications avoided.