The objective of this prospective follow-up study (median follow-up time 20 years) was to investigate whether there are differences in cardiovascular disease (CVD) and all-cause mortality among hypertensive men and women by awareness, treatment and blood pressure (BP) control status. The study was carried out among 20,358 men and 21,537 women aged 25-64 years living in Eastern and south-western Finland within the framework of the North Karelia Project and the Finrisk studies. Risk factors of CVD and life-style habits were assessed by a self-administered questionnaire, BP and laboratory measurements. The participants were classified into five groups according to their BP status: (i) normotensive, (ii) patients treated with antihypertensive drugs and controlled for HT, (iii) patients treated with antihypertensive drugs but uncontrolled for HT, (iv) hypertensive people aware of their HT but untreated, (v) hypertensive people unaware of their hypertension (HT). In men, all-cause and CVD mortality was significantly higher in all HT subgroups compared with the normotensive group. The risk increase for CVD mortality was 49-125% and 27-79% for all-cause mortality, respectively. Treated and controlled hypertensive women at baseline did not have any increase in CVD (hazard ratio (HR) 1.14; 95% CI 0.89-1.46) or all-cause mortality (HR 1.09; 95% CI 0.72-1.67) compared with normotensive women. In men, however, the corresponding HR were 1.58 (95% CI 1.28-1.96) for CVD and 2.25 (95% CI 1.70-2.99) for all-cause mortality. Treated hypertensive women seem to benefit from achieving normal BP.