The observation of a case of male pseudohermaphroiditism offered the opportunity for an analytical review of this pathology. Clinical features and failure to respond to prolonged testosterone treatment allowed this case to be included in the group characterized by androgen resistance of which a recent classification distinguishes various types on the basis of phenotypic and hormonal features. Incomplete virilization of the external genitals and high testosterone and LH plasma levels were evidence in favour of the conclusion that the case should be classified as incomplete male type I pseudohermaphroditism.