Obstructive sleep apnea (OSA) is characterized by repetitive partial and total collapse of the upper airway that induces stressful arousals throughout sleep to reestablish breathing. Although estimates vary, prevalence has been reported as high as 20% in the adult population. OSA is common in several chronic diseases, the most common of which is obesity. Evidence is strong that OSA increases the risk of hypertension and both fatal and nonfatal cardiovascular events. Several mechanisms linking OSA to hypertension have been proposed, with increased sympathetic activation implicated as the prime mediator. This review summarizes recent data on the influence of OSA on blood pressure, the effect of standard OSA therapy on improving blood pressure, and the potential of lifestyle modification for further decreasing hypertension risk. Challenges confronting the investigation of blood pressure outcomes in response to treatment in OSA patients are discussed.