Swimming, water jogging, and aqua aerobics are lifetime physical activities that provide many health benefits comparable to those of walking and running. Research on the association between swimming and mortality is scarce, however. To evaluate the association between different types of physical activity and all-cause mortality, we studied 40,547 men age 20-90 years who completed a health examination during 1971 – 2003. Cox proportional-hazards regression was used to estimate the relative risks according to physical activity exposure categories. A total of 3,386 deaths occurred during 543,330 man-years of observation. After adjustment for age, body-mass index, smoking status, alcohol intake, and family history of cardiovascular disease, swimmers had 53%, 50%, and 49% lower all-cause mortality risks than did men who were sedentary, walkers, or runners, respectively (p < 0.05 for each). Additional adjustment for baseline prevalent diseases did not change the inverse association between different activities and all-cause mortality. In conclusion, swimmers have lower mortality rates in comparison with those who were sedentary, walkers, and runners.