Continuous positive airway pressure (CPAP) is the first-line treatment of obstructive sleep apnea (OSA). Obstructive sleep apnea is a predictor of cardiovascular (CV) events. In this meta-analysis, we evaluated the effect of CPAP on left ventricular ejection fraction (LVEF), CV events, CV mortality, and all-cause mortality in patients with OSA. Nine articles (n = 9610 patients) were analyzed. Four different meta-analyses were performed: evaluation of LVEF, assessment of all-cause mortality, CV mortality, and CV events. Continuous positive airway pressure treatment was associated with a significant increase in LVEF (mean difference: 2.1%, 95% confidence interval [CI]: 0.8%-3.4%). There was a nonsignificant reduction in all-cause mortality (hazard ratio [HR]: 0.92, 95% CI: 0.73-1.15) but a significant reduction of 66% in the risk of CV mortality associated with the CPAP treatment (HR: 0.34, 95% CI: 0.17-0.68, P = .002). There was a nonsignificant reduction in the risk of CV events in the CPAP-treated patients (HR: 0.84, 95% CI: 0.60-1.18, P = .31). Our meta-analyses showed that CPAP treatment improves LVEF and could have a beneficial effect on CV mortality.