Objective. To determine the dynamics of the clinical and psychological characteristics on the background of 1 month of CPAP therapy in patients with obstructive sleep apnea syndrome (OSA) and arterial hypertension (AH), both adherent and non-adherent to the treatment. Methods. The study included 180 patients with OSA and AH. Upon enrollment, anthropometric data, the results of polysomnography and cardiorespiratory studies, Beck depression scale, Spielberger personal and situational anxiety scale, Epworth daytime sleepiness scale, Pittsburgh sleep quality questionnaire and Quality of Life (WHO QOL-100) questionnaire were analysed. Out of 40 patients undergoing CPAP therapy, 30 patients were adherent to the treatment within a month. The adherence criterion was considered to be the usage of the CPAP device more than 4 hours per night, more than 5 days a week. In this article, the dynamics of the questionnaire scales is given only for those who were adherent to CPAP therapy. Results. Patients with OSA and AH adherent to CPAP therapy showed a statistically significant reduction in daytime sleepiness and depression, as well as improved quality of sleep and quality of life in the physical domain within 1 month of using CPAP therapy. Conclusion. Even short-term use of CPAP therapy in patients with OSA and AH leads to a reduction in daytime sleepiness and depression, improved quality of sleep and quality of life in the physical domain.