During the period 1953 to 1960, 52 boys with cryptorchism were treated with human chorionic gonadotrophin. The majority of patients were treated after the age of eleven. The material presented is in several respects a selected one as patients with retractile testes and with mechanical obstruction to the descent were as far as possible excluded. The total dose of gonadotrophin varied between 6600 and 17400 IU which is considered a moderate dose. The result was satisfactory with regard to testicular position, size and consistency in only 10 patients or expressed in terms of individual testes in 16 cases. Factors that may have influenced the incidence of descent are discussed.