The syndrome of male pseudohermaphroditism, caused by a deficiency of the enzyme 5-alpha reductase, results in a selective decrease in dihyrotestosterone. Culture is an important part of the context in which decisions are made on sex assignment of patients with abnormalities of the external genitalia. In Turkey, patients with ambiguious genitalia are diagnosed very late and corrective surgery is usually performed during or after puberty. Here we present a case with 5-alpha reductase deficiency who was diagnosed at puberty and followed-up for 10 years.