SummaryWe report the case of a young female patient who presented, at the age of 13, a severe glucose intolerance with very high plasma insulin levels. She was immediately treated with insulin, a treatment which could be stopped 9 months later while the glucose tolerance remained slightly abnormal inspite of a persistent hyperinsulinism. Virilism and acanthosis nigricans developped soon after puberty. The level of erythrocyte insulin receptors was markedly diminished whereas anti-receptor antibodies were not detected. Thus, the patient presented a syndrome of type A (originally described by Kahn) associating glucose intolerance (or diabetes), viri lism and acanthosis nigricans. This congenital syndrome, occurring in young females, is characterized by a severe insulin resistance due to a decreased number (or impaired function) of insulin receptors. Our patient was treated with an association of cestrogen-antiandrogen which resulted in a rapid decrease of hirsutism without apparent modification of glucose tolerance and hyperinsulinism.