The association between leisure time physical activity and the risk of all-cause and cardiovascular disease mortality was analyzed in a Finnish cohort of 1,072 men age 35-63 years who were followed up for 10 years and 10 months. During the period, 168 deaths were recorded, 93 of which were the result of cardiovascular diseases. Leisure time physical activity was assessed by several measures: 1) a single question combining an estimate of the frequency and intensity of the total amount of leisure time physical activity, 2) a compiled measure of leisure time physical activity derived from three separate questions concerning the intensity and frequency of activity, 3) a physical energy expenditure index computed as an estimate of weekly energy expenditure for leisure time activity and commuting to work, 4) 16 separate specified activities of daily living and domestic chores included in the leisure time physical activity index. The association between baseline leisure time physical activity and the risk of death was assessed using the Cox proportional hazards model. After adjustment for potential confounders, the leisure time physical activity energy expenditure index and participation in several specific activities of daily living and domestic chores showed that the mortality risk for all causes and cardiovascular diseases was highest in the most sedentary men. With respect to the leisure time physical activity energy expenditure index, sedentary men ( those with an estimated weekly energy expenditure in leisure time physical activity of < 800 kcal) had an increased risk of 2.74 (95% confidence interval 1.46-5.14) for all-cause mortality and a risk of 3.58 (95% confidence interval 1.45-8.85) for cardiovascular disease mortality compared with the most active persons (those with an estimated weekly energy expenditure in leisure time physical activity of at least 2,100 kcal) when age, initial health status, marital status, employment status, and smoking were controlled.