This study investigated if behavioral factors, treatment with behavioral support, readiness to change, fall self-efficacy, and activity habits could predict long-term adherence to an exercise program. Included in this study were 114 community-dwelling older adults who had participated in one of two home-based exercise interventions. Behavioral factors associated with adherence to the exercise program over 52 weeks were analyzed. The behavioral factors, specifically activity habits at baseline, significantly predicted adherence to the exercise program, with an odds ratio = 3.39, 95% confidence interval [1.38, 8.32], for exercise and an odds ratio = 6.11, 95% confidence interval [2.34, 15.94], for walks. Being allocated to a specific treatment including motivational interviewing was also significantly predictive: odds ratio = 2.47, 95% confidence interval [1.11, 5.49] for exercise adherence. In conclusion, activity habits and exercise in combination with motivational interviewing had a significant association with adherence to the exercise program at a 1-year follow-up.