Purpose: This study was to determine the effects of exercise program for knee osteoarthritis on the physical fitness in elderly. The progressive exercise program included flexibility, strength, endurance, active range of motion and function activities. Methods: Nineteen subjects with osteoarthritis of the knees randomized to exercise group(n=10) or control group(n=9), but fourteen subjects completed the trial with an adherence of 70% to the intervention and 77% to the control. The physical fitness(back muscle strength, grip strength, flexibility, muscle power, agility, equilibrium) were evaluated with Helmas(Health Management System) made by Sewoo system at pre- and post- intervention. Results: The data were analysed with the two-way repeated ANOVA and paired t-test. The physical fitness had no difference among the groups and times except muscle power. Within experimental group, muscle power and agility were significantly increased between pre and post intervention, while the control group showed no change. Conclusion: Exercise program for knee osteoarthirits appear to be effective in muscle power and agility.