Purpose: This study assessed the impact of a low cost, multicomponent physical activity intervention for older adults with lower extremity osteoarthritis. Design and Methods: A randomized controlled trial compared the effects of a facility-based multiple-component training program followed by home-based adherence (n = 80) to a wait list control group (n = 70). Assessments were conducted at baseline and at 2 and 6 months following randomization. The training program consisted of range of motion, resistance training, aerobic walking, and education-group problem solving regarding self-efficacy for exercise and exercise adherence. All training group participants developed individualized plans for posttraining adherence. Results: Relative to the persons in the control group, individuals who participated in the exercise program experienced a statistically significant improvement in exercise efficacy, a 48.5% increase in exercise adherence, and a 13.3% increase in 6-min distance walk that were accompanied by significant decreases in lower extremity stiffness at 2 and 6 months. Program participants also experienced a significant decrease in lower extremity pain and a borderline significant improvement in efficacy to adhere to exercise over time at 6 months (p= .052). In contrast, persons in the control group deteriorated over time on the efficacy and adherence measures and showed no change on the other measures. No adverse health effects were encountered. Implications: These benefits indicate that this low-cost intervention may hold great promise as one of a growing number of public health intervention strategies for older adults in the United States with osteoarthritis.