OBJECTIVE: Our objective was to investigate what impact 1 year of effective nocturnal continuous positive airway pressure (CPAP) treatment had on general and functional aspects of sexuality in male patients with a confirmed diagnosis of obstructive sleep apnoea (OSA). METHODS: Before and after 1 year of CPAP treatment, a total of 207 CPAP-compliant male patients (age 26-77) received a survey with questions drawn from two self-administered questionnaires on sexuality - Life Satisfaction 11 (LiSat-11) and brief sexual function inventory (BSFI). For assessment of daytime sleepiness, we used the Epworth sleepiness scale (ESS). RESULTS: Response rate was 76%. We found no significant changes in satisfaction with relation to partner or life as a whole, but satisfaction with sexual life (LiSat-11) and both general and functional aspects of sexuality (BSFI) were significantly improved after 1 year of CPAP treatment. ESS score decreased significantly after 1 year of CPAP treatment. CONCLUSION: One year of CPAP treatment improves all aspects of sexual function in male patients with OSA. Our data indirectly suggest that organic factors are the most likely explanation to these improvements.