Objectives: Program method, program deliverer and participant preference may be important factors in increasing physical activity adherence and program effectiveness. To investigate this, we compared two physical activity interventions in middle-aged adults. Methods: Using a pragmatic quasi-experimental design, sedentary community dwelling 50 - 65 year olds (n = 2105) were recruited to a non-randomized 6-month community group exercise program (n = 93) or a physiotherapist-led home-based physical activity program (n = 65). The primary outcome was physical activity adherence derived from exercise diaries. Secondary outcomes included the Active Australia Survey, aerobic capacity (step- test), quality of life (SF-12v2), blood pressure, waist circumference, waist-to-hip ratio (WHR) and body mass index. Results: Home-based participants were more likely to be younger, working full-time and not in a relationship (p Thirty-three percent of the group participants attended ≥ 70% of group exercise sessions. Ninety percent of home-based participants received ≥ 4 of the planned 6 telephone support calls. Intention-to-treat analysis found adherence to the physical activity sessions prescribed was the same for both interventions (26% ± 28% vs. 28% ± 35%). Both interventions significantly increased the number of participants achieving self-reported “sufficient” physical activity (p ≤ 0.001) and significantly decreased waist circumference (p WHR (p 0.05). Conclusion: The physiotherapist- led home-based physical activity program, requiring few resources, appears to have increased the adoption of physical activity and adherence to physical activity program requirements for sedentary middle-aged adults. The home-based program, providing equivalent health benefits to the group exercise program, may be particularly suitable for those not interested in or unable to attend a group exercise program. Clinical Trial Registration number Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN126 1000890932.