BACKGROUND: Given the concerns about low rates of physical activity among low-income minority youth, many community-based organizations are investing in the creation or renovation of public parks to encourage youth to become more physically active. To what degree park renovations accomplish this goal is not known. METHODS: We used the System for Observing Play and Recreation in Communities (SOPARC) to measure park users and their physical activity levels before and after 2 parks were renovated. We compared findings with 4 parks: 2 that were unrenovated parks and 2 that were undergoing renovation. We also surveyed park users and local residents about their use of the parks. RESULTS: Compared with parks that had not yet been renovated, the improved parks saw more than a doubling in the number of visitors and a substantial increase in energy expended in the parks. Increased park use was pronounced in adults and children, but was not seen in teens and seniors. Park renovations were associated with a significantly increased perception of park safety. CONCLUSIONS: Park improvements can have a significant impact on increasing park use and local physical activity.