BACKGROUND: Despite the emerging body of research on the potential of physical activity to improve learning and academic achievement, conclusive evidence regarding the effects of physical activity on academic achievement is lacking. The objective of this study was to determine the impact of a physical activity intervention program on academic performance. METHODS: A controlled cross-sectional design was used to investigate the hypothesis that the intervention program would increase the proportion of students in grade 5 who achieved the national learning goals in Swedish, mathematics, and English compared with 3 reference schools. Academic results from the years prior to and during the intervention program were analyzed. Logistic regression analyses assessed the odds of achieving the national learning goals when the intervention program was integrated into the elementary curricula. RESULTS: Higher proportions of students in the intervention school achieved the national goals in all 3 subjects compared with the reference schools after initiation of the intervention program. The odds for achieving the national learning goals in the intervention school increased 2-fold (p < .05), whereas these odds either did not change or decreased in the reference schools. CONCLUSION: Promoting physical activity in school by means of a curriculum-based intervention program may improve children's educational outcome.