Ten narcoleptic patients were treated daily with Mazindol 2-6 mg for 42.2 months (31-63 months). The response was excellent on narcoleptic attacks in 6 and on cataplexy in 7 cases. However, the nocturnal sleep disturbance persisted unchanged. The improvement was poor in 1 case and inexistant in 1 subject. Minor side effects (dry mouth) occurred in 3 cases, and urinary retention obliged to stop the medication in 2 cases.