Obstructive sleep apnea (OSA) is often linked to high blood pressure and has a particularly high prevalence in patients with resistant hypertension. The effect of continuous positive airway pressure (CPAP) therapy on blood pressure (BP) values has been evaluated in several short-term clinical trials with conflicting results. Our aim was to investigate the role of long-term CPAP treatment in achieving BP control in patients who associate OSA and resistant hypertension. We have included in the study 33 patients with resistant hypertension, diagnosed with OSA in our sleep lab. Data was collected initially and after a mean follow-up period of 4 years. Patients were divided into 2 groups according to the use of CPAP therapy. Patients under CPAP therapy (n = 12) exhibited a higher reduction in both systolic and diastolic pressure and BP control was achieved in 75% of cases, while patients without CPAP treatment (n = 21) remained with refractory hypertension in proportion of 90.5%. A de-escalation of antihypertensive drug regimen by discontinuation of 1 or more drugs was observed in 41.6% (n = 5) of patients from CPAP group and in the other 33.4% (n = 4) the medication remained unchanged, but BP control was reached. Using a direct logistic regression model for examining the impact of different confounders on the probability of diagnosis of resistant hypertension at follow-up, the only statistically significant predictor found was the lack of CPAP usage.