Exercise systematically improves physical and psychological performances on a wide range of measures, but the links between them are rarely examined for the high homogeneous group of institutionalized veterans. This study aims to investigate the exercise intervention effects on both depressive symptoms and body-balance. Samples were divided into experimental-group (N = 11, mean age = 80.67) and the control-group (N = 10, mean-age = 82.54). The experimental-group received 10 sessions of exercise intervention, including aerobic cycling and leg stretching (muscular endurance), while the control-group attended lecture sessions on health education. Depressive symptoms: the findings show the intervention has no significant intragroup effect on either the experimental-group or the control-group; but a high and median effect-size (EF with Cohen's d) was found for both the experimental and the control group (d = 0.916 and 0.504, respectively). The intergroup difference was small (p = 0.748; d = 0.136). Balance-ability: the findings show no statistically significant intragroup effect on the 5-stage balance test within the experimental-group, and the EF is low. In the control-group, health education intervention had no improvement on the 5-stage balance test, but there was a moderate decrease in balance Stage-4 (d = -0.626). Additionally, the strong intergroup effect (d = 1.621, p = 0.003) indicated that the experimental-group is superior to the control-group at Stage-4, and there was a moderate effect at stage-3 and stage-5 (d = 0.567 and 0.495, respectively). The current study shows that exercise can help adults older than 80 to ameliorate depressive symptoms and enhance body balance ability, and the findings deserve more attention.