Background: Physical inactivity is a primary contributor to decreasing functional physical fitness and increasing chronic disease in older adults. Purpose: This study assessed the health-related benefits of ExerStart for Lay Leaders, a 20-week, community based, peer-led, low-impact exercise program for older adults. ExerStart focuses on aerobic endurance, muscular strength, flexibility, and balance. Methods: Using a pre/posttest evaluation design, researchers examined the effects of the program on 432 older adults in St. Louis, Missouri, and Houston, Texas. Participants completed self-report surveys as well as observed functional physical fitness assessments. Results: Participants in ExerStart for Lay Leaders significantly improved their perceived satisfaction with body function, functional physical fitness, perceived overall health, and body mass index. Discussion: This study adds to the evidence that older adults benefit from structured, peer-led exercise programs. The increased physical fitness, if maintained, may lead to a decrease in falls, adult obesity, and nursing home placements. Translation to Health Education Practice: The current research has important implications for implementing outcome-based and cost-effective health education programs for older adults, including using peer leaders as a cost reduction technique to implement and disseminate research informed programs into community settings.