The aim of the present study was to examine the long-term impact of midlife blood pressure (BP) on mortality, comorbidity, and health-related quality of life (HRQoL) in old age. These are longitudinal analyses of the Helsinki Businessmen Study, a cohort of business executives, born in 1919-1934, whose BP was measured between 1964 and 1973 (n = 3267). Comorbidity and HRQoL with RAND-36 [Short Form (SF)-36] were assessed from questionnaires in 2000; mortality up to 31 July 2012 was ascertained from national registers. Baseline BP was categorized as normal, less than 120  mmHg systolic and less than 80  mmHg diastolic (n = 121); prehypertension, 120-139  mmHg systolic or 80-89  mmHg diastolic (n = 2131); stage 1 hypertension, 140-159 mmHg systolic or 90-99  mmHg diastolic (n = 757); and stage 2 hypertension, more than 160  mmHg systolic or more than 100  mmHg diastolic (n = 258). Main outcome measures were long-term mortality, comorbidity, and HRQoL in old age. During the 48-year follow-up, 2013 men (61.6%) died. There was a graded relationship between BP and total mortality (P < 0.001). The men with normal BP had the lowest mortality; the age-adjusted difference in mean survival was 7.5 years between the normal and stage 2 baseline BP groups, and 11.2 months between normal and prehypertension groups. Lower BP in midlife was associated with better scores in the physical functioning (P-linear trend <0.001) and general health (P = 0.01) scales of RAND-36 in old age. RAND-36 scales associated with mental health were not affected by midlife BP. Lower BP in midlife is associated with longer life and better physical HRQoL in old age.