Nasal continuous positive airway pressure (NCPAP) represents a real advance in the management of obstructive sleep apnea (OSA). Our data show that except for awakenings, all sleep and respiratory parameters were significantly improved (p<0.05) in favor of the group treated with NCPAP. A main problem with NCPAP is the acceptance by the patient; it also may disturb the sleep, at least, on short term basis and, in a small number of patients, it does not correct the apneas. In our patients series, males responded better to NCPAP than females.