Background: Patients with obstructive sleep apnoea (OSA) are at increased risk of severe course of COVID-19. Vaccination remains to be the most effective prevention of complicated courses of infection. The best contemporary conservative treatment of OSA is continuous positive airway pressure (CPAP) therapy.Purpose: To compare vaccination acceptance and outcomes of COVID-19 infection between OSA patients adhering to the CPAP therapy and those who rejected CPAP and surgical therapy.Patients and Methods: Subjects were divided into two groups: group A (N = 167) were individuals with sufficient CPAP adherence (more than 4 hours per night on average) over the last 10 years. Group B (N = 106) were individuals who did not use the CPAP therapy at all and had no indications to surgical therapy.Results: Three patients in group B died, and one had a severe course of COVID-19. None of the patients in group A died or experienced a severe course of COVID-19. Group A had a significantly higher proportion of males (77.8% compared to 66% in group B) and all parameters of OSA severity. The vaccination status was similar among both groups, with a complete triple dose vaccination rate of 69.5% and 67.9% in groups A and B, respectively. Conclusion: The results show that the patients with OSA adherent to CPAP therapy were less likely to experience a severe course of COVID-19 or death than the OSA patients non-compliant with therapy, despite the former group having more severe OSA. This result underlines the importance of adherence to CPAP therapy in OSA.