Regular exercise has been recommended to improve balance, strength, and coordination in older persons. In this study, 44 persons, aged 50 to 75 years (mean 62.4 yrs) underwent assessments of quadriceps strength, reaction time, neuromuscular control, and body sway on two occasions before beginning a 10-week exercise program. The subjects were retested for the same measures at the end of the program. The mean number of classes attended for the 40 subjects who were retested was 16.2 (range 11 to 19). On completion of the program, the subjects showed improved performance in the tests of quadriceps strength, reaction time, body sway on a firm surface with the eyes closed, and a compliant surface with the eyes open and closed. In contrast, a group of nonexercisers showed no improvements in any of the test measures. These results suggest that exercise may play a role in improving a number of sensorimotor systems that contribute to stability in older persons.