Twenty-one women, aged 57 to 75 years, who had been taking part in exercise programs for periods of 12 months or more underwent tests of muscle strength, reaction time, proprioception, and body sway. The performance of these women in the tests was compared with 21 women of the same age who were not taking part in any organized physical activity and were not exercising more than 30 minutes a day. The women who had been taking part in the exercise program performed significantly better in the tests of quadriceps strength, reaction time, and sway on a compliant surface than the nonexercising women. The exercisers also had lower body mass index scores. These pilot results suggest that exercise may play a role in improving a number of sensori-motor systems that contribute to stability, and that exercise of this nature may help prevent falls in older women.