The purpose of the study was to assess the prognostic significance of out-of-the-office blood pressure (BP) measurement in older patients in general practice, and to compare the results for BP measured in the office, at home and during 24-h ambulatory monitoring. All registerd patients who were 60 years or older were eligible for the study, except when bedridden, demented or admitted in a home for sick elderly people, or when they had suffered a myocardial infarction or stroke. After baseline measurements in 1990-1993, incidence of major cardiovascular events (cardiovascular death, myocardial infarction and stroke) was ascertained in 2002-2003 and related to the BPs by use of multivariate Cox regression analysis. Age of the 391 patients averaged 71+/-9 years; 40% were men. During median follow-up of 10.9 years, 86 patients (22%) suffered a cardiovascular event. The adjusted relative hazard rate, associated with a 1 s.d. increment in systolic BP was 1.13 for office BP (NS), and, respectively, 1.32, 1.33 and 1.42, for home, daytime and night time BP (P< or =0.01 for all). Results were similar for diastolic BP. The prognostic significance of all out-of-the-office BPs was independent of office BP. The prognostic value of home BP was equal to (systolic) or even better (diastolic) than that of daytime BP. Night time BP predicted cardiovascular events independent of all other BPs. Prognosis of white-coat hypertension was similar to that of true normotension, but better than in sustained hypertension. In conclusion, the prognostic value of home BP is better than that of office BP in older patients in primary care, and is at least equal to that of daytime ambulatory BP. The prognosis of patients with white-coat hypertension is similar to that of true normotensives.