Seven hundred and twenty-four people (541 female, 183 male), aged 84-88 years and living at home in the city of Tampere, Finland, accepted our invitation to be examined in the outpatient department of the local geriatric hospital. These subjects were re-examined annually, and their fate was followed for 3 years. The blood pressure level was a prognostic sign for mortality during the first year after its measurement. The lowest mortality rate was found among those subjects with systolic blood pressure between 140 and 169mmHg and diastolic blood pressure between 70 and 99mmHg. Blood pressures outside of these ranges were associated with increased mortality rates, particularly cardiac and coronary mortality. The mortality rate was especially high among those whose systolic blood pressure had decreased to low levels in the year before, but was lower in those whose systolic blood pressure had decreased from high to middle levels (140-169 mmHg) than in those with consistently high systolic blood pressure. Eventual institutionalization was more common in those with low systolic blood pressure.