We studied the association of glucose intolerance with total and cause-specific mortality during a 5-year follow-up of 637 elderly Finnish men aged 65 to 84 years. Total mortality was 276 per 1000 for men aged 65 to 74 years and 537 per 1000 for men aged 75 to 84 years. Five-year total mortality adjusted for age was 364 per 1000 in diabetic men, 234 per 1000 in men with impaired glucose tolerance and 209 per 1000 in men with normal glucose tolerance. The relative risk of death among diabetic men was 2.10 (95% confidence interval 1.26 to 3.49) and among men with impaired glucose tolerance 1.17 (95% confidence interval 0.71 to 1.94) times higher compared with men with normal glucose tolerance. Cardiovascular disease was the most common cause of death in every glucose tolerance group. The multivariate adjusted relative risk of cardiovascular death was increased (1.55) in diabetic patients, albeit non-significantly (95% confidence interval 0.84 to 2.85). Diabetes resulted in an increased risk of cardiovascular mortality among men aged 65-74 years but not among the 75- 84-year-old men. Relative risk of death from non-cardiovascular causes was slightly increased among diabetic subjects. In conclusion, diabetes mellitus is a significant determinant of mortality among elderly Finnish men.