Background: School initiatives aimed at increasing physical activity (PA) may improve the health of children in low-income communities. Methods: Assessors completed 5909 observations of students' PA during leisure periods using a validated instrument in 19 schools in low-income Latino communities. We examined relationships between school environment factors (eg, presence of playground equipment) and levels of moderate-to-vigorous physical activity (MVPA). RESULTS Overall, 16.4% of students were engaged in vigorous activity, lower than reported in prior analyses. Consistent with earlier reports, boys were more engaged in vigorous PA than girls (18.6% vs 13.2%). Playground equipment, such as balls and jump ropes, were present in 27.5% of activity areas. Supervision was present in 83.1% of observations; however, staff members were only observed leading organized activity in 1.7%. Playground equipment was associated with higher rates of MVPA, particularly among elementary boys (p < 0.0001). Staff supervision was not associated with MVPA, possibly because staff members rarely led organized activity. Conclusions: We found low rates of leisure time PA among students in this low-income Latino community. The presence of playground equipment was favorably associated with activity levels. Increasing the availability of playground equipment might promote activity among children in similar populations.