Obstructive sleep apnea and hypertension are closely related diseases. The lowering effect of continuous positive airway pressure (CPAP) on blood pressure (BP) control is modest and concomitant antihypertensive therapy is still required. However, the best antihypertensive regimen for BP control in patients with OSA remains unknown. We aimed to investigate a hypothetical association between ongoing antihypertensive medication and BP control rates in patients with OSA. We conducted a prospective observational study in a cohort of 205 patients with OSA and hypertension who underwent a sleep study and 24-h ambulatory blood pressure monitoring (ABPM). Ongoing antihypertensive medication profile was recorded. Logistic regression models were used to investigate the association between antihypertensive regimen and BP control, before (n = 205) and, when applicable, after CPAP adaptation (n = 90). One hundred and fifty-five patients (155/205) were being treated with 31 different antihypertensive regimens. At baseline, the antihypertensive regimens and the number of antihypertensive drugs were not associated with BP control (p = 0.847; p = 0.991). After CPAP adaptation, a decrease in median night-time systolic and diastolic BP was observed (p = 0.001; p = 0.006). Nevertheless, the lack of association between antihypertensive regimens and the number of antihypertensive drugs and BP control remained (p = 0.864; p = 0.800). Our findings confirm that although CPAP improves nocturnal BP, this improvement is not sufficient to control blood pressure for 24 h. This study shows, for the first time, that in patients with OSA, there is no association between BP control and both the antihypertensive regimen and the number of antihypertensive drugs.