Patients with obstructive sleep apnea/hypopnea syndrome (OSAHS) treated by continuous positive airway pressure (CPAP) need to use long-term CPAP to prevent cardiovascular disease. The method of survival analysis was used to allow for long-term CPAP use in 72 patients who were prescribed a CPAP. During a mean follow-up of 22+/-15 months, one patient died and 17 patients stopped their treatment, 29% of them in the first 6 months. In compliant patients, the median value of daily CPAP use was 4.5hours. Kaplan Meier analysis showed that 92% of patients were still using CPAP at 6 months, 83% at 12 months and 59.9% at 3 years. Chronic obstructive pulmonary disease was identified as a predictor factor of long-term CPAP use (OR=4.53, p=0.01). CPAP is a well-accepted long-term therapy for OSAHS with 60% of patients continuing to be compliant with treatment at 3 years.