We evaluated the impact of outdoor exercise equipment (FZ, Fitness Zones) in 12 parks serving diverse populations. We used the System for Observing Play and Recreation in Communities (SOPARC) to assess use and estimate energy expenditure prior to and twice after FZ installation. Park use increased more in FZ parks than in 10 control parks that did not get equipment, but the difference was not statistically significant. However, self-reports of being a new park user increased more in FZ parks, and estimated energy expenditure in FZ parks was higher at both follow-ups than at baseline. Installing Fitness Zones appears to be cost-effective (10.5 cents/MET increase) and most successful in parks in densely populated areas with limited facilities. Longer-term follow-up measures are needed to determine if the early increases in physical activity associated with the Fitness Zone installations are sustained.