Obstructive sleep apnea is common and considered to be a risk factor for hypertension, stroke and coronary disease. Accordingly, the presence of sleep apnea is probably a predictor of premature death. Continuous positive airway pressure is an effective treatment of obstructive sleep apnea. It has been demonstrated that such treatment improves daytime sleepiness and quality-of-life. To determine mortality in obstructive sleep apnea patients treated with nasal continuous positive airway pressure, we followed 296 patients given continuous positive airway pressure for 11 years 6 months. At the end of the study 26 of the 296 patients had died, mainly from cardiovascular disease. Mortality was 7% (95% confidence interval: 3%-9%) at 5 years. Three independent factors of death identified by forward stepwise selection were included in a Cox analysis. These factors were 1) smoking as a categorical covariate (>30 pack-years), 2) age and 3) forced expiratory volume in 1 s. When the 52 patients with an associated chronic obstructive pulmonary disease (forced expiratory volume in 1 s/vital capacity<0.65) with obstructive sleep apnea were excluded form analysis, mortality of the 244 remailing patients was 2% at 5 years, a rate observed in the general population. Subsequently, it appears that nasal continuous positive airway pressure corrects for the risk of premature death suspected in obstructive sleep apnea patients. Mortality in obstructive sleep apnea patients treated with continuous positive airway pressure is near to that of the general population, particularly when patients with an associated chronic respiratory disease are excluded.