We report a case of anorchia in conjunction with isolated idiopathic hypogonadotropic hypogonadism. Plasma levels of LH, FSH, TSH and testosterone were abnormally low. Administration of human chorionic gonadotropin caused no increase in plasma testosterone, and injection of luteinizing hormone-releasing hormone resulted in no change in plasma gonadotropins. We discuss the embryology and hormonal status of this patient.