Project SPARK evaluates multiple effects of a health-related physical education (PE) program for elementary school students. Seven schools were randomly assigned to one of three conditions: usual PE or control, trained classroom teachers, or PE specialists. The intervention was implemented throughout the fourth and fifth grades. Data are available from one cohort of 550 children who were measured in the fall and spring of both grades. Adiposity was assessed by triceps and calf skinfolds, and body mass index (BMI) was also measured. Data at each measurement point were analyzed by ANOVAs, covarying for baseline values. At no measurement point were there significant group differences in total skinfold. At both fifth grade measurement points for boys and girls, however, there was a trend for the control group to have higher skinfold values than the two intervention groups. At the final measure, the difference between the highest and lowest groups was about 3 mm for girls and 2 mm for boys. BMIs were significantly lower at some measurement points for boys and girls, but this could be due to increased lean body mass in intervention students. After two years, there was a trend for the children exposed to the PE intervention to have lower levels of body fat, but the differences were not significant.