Background: Functional fitness is essential for the autonomous performance of activities of daily living. The functional fitness of the elderly includes several components: strength, aerobic training, flexibility, balance, and body composition. Objectives: To assess changes in the functional fitness of institutionalized elderly based on a Rehabilitation Nursing Program using moderate-intensity physical activity. Methodology: Pre-test/post-test design with control group. The intervention program included three 30-minute sessions per week, for a period of 6 months. Functional fitness was assessed using the Functional Fitness Test (FFT) battery for older adults. Fifteen participants were assigned to the intervention group (IG), and ten participants to the control group (CG). Results: A significant increase (p<0.05) of grip strength, arm curl strength, mobility, agility/dynamic balance, and one-leg balance was observed in the IG (85.9 ± 6.1 years). The CG (85.8 ± 4.6 years) showed no significant changes in any of the functional fitness components. Conclusion: The results suggest an improvement of the functional fitness of the elderly in the IG.