The specific health benefits achieved from different forms and patterns of leisure-time physical activity are not established. We analyzed the mortality in a cohort of Swedish golf players. We used the Swedish Golf Federation's membership registry and the nationwide Mortality Registry. We calculated standardized mortality ratios (SMR) with stratification for age, sex, and socioeconomic status. The cohort included 300 818 golfers, and the total number of deaths was 1053. The overall SMR was 0.60 [95% confidence intervals (CIs): 0.57-0.64]. The mortality reduction was observed in men and women, in all age groups, and in all socioeconomic categories. Golfers with the lowest handicap (the most skilled players) had the lowest mortality; SMR=0.53 (95% CI: 0.41-0.67) compared with 0.68 (95% CI: 0.61-0.75) for those with the highest handicap. While we cannot conclude with certainty that all the 40% decreased mortality rates are explained by the physical activity associated with playing golf, we conclude that most likely this is part of the explanation. To put the observed mortality reduction in context, it may be noted that a 40% reduction of mortality rates corresponds to an increase in life expectancy of about 5 years.