Although NCPAP is the most efficient nonsurgical treatment for patients with OSA, many patients do not accept sleeping with a nose mask. To determine the factors influencing acceptance, treatment with NCPAP was offered to 95 patients with an AHI greater than 15. After the first night on NCPAP, 47 of 65 patients decided to have NCPAP as a home therapy. Excessive daytime sleepiness was more frequently reported by acceptors than refusers. The frequency of complaints about psychomental symptoms such as poor mental performance and bad memory, was not different between the two groups. There was a close correlation between the rate of acceptance and the AHI as well as the number of positive answers to questions about symptoms of daytime sleepiness in a questionnaire, which correlated with the number and length of apneas. Acceptance of NCPAP was found to be dependent on the subjective feeling of impairment by hypersomnolence due to OSA.