Several epidemiological and experimental studies have demonstrated a close relationship between sleep-disordered breathing and cardiovascular disease. Obstructive sleep apnoea has been linked to hypertension in a dose-dependant and time-related manner. Postulated underlying mechanisms involve autonomic nervous system alterations, chemoreceptor and baroreceptor responsiveness impairment, higher levels of vasoactive hormones and impaired endothelial function. Continuous positive airway pressure (CPAP) therapy for obstructive sleep apnoea may significantly improve blood pressure control and influence target organ damage, previously ascribed to hypertension alone.