Sleep disordered breathing is frequently associated with repeated arousals and hypoxia resulting from intermittent partial or complete collapse of upper airway during sleep. There is an emerging recognition of the association of this disorder with metabolic abnormalities, coronary artery disease, congestive heart failure and hypertension. Of these conditions, the data associating obstructive sleep apnea and hypertension are the most compelling. This review evaluates the recent literature investigating this association and identifies areas where additional research is needed.