Advocates of quality daily physical education for prepubescent children frequently encounter the argument that such initiatives will harm academic progress. The impact of daily physical education upon the academic performance of primary school students is thus reviewed with particular reference to studies conducted in Vanves (France), Australia, and Trois Rivieres (Quebec). When a substantial proportion of curricular time (14-26%) is allocated to physical activity, learning seems to proceed more rapidly per unit of classroom time, so that academic performance matches, and may even exceed, that of control students. Children receiving additional physical education show an acceleration of their psychomotor development, and this could provide a mechanism for accelerated learning of academic skills. Other potential mechanisms include increased cerebral blood flow, greater arousal, changes in hormone levels, enhanced nutrient intake, changes in body build, and increased self esteem. Academic teachers may also favor the enhanced physical education program, creating "halo" effects, and the resulting release time may enhance their academic teaching. Irrespective of mechanisms, the implication for public policy is that daily required physical education can be introduced when a child enters primary school without compromising academic development. Given the importance of establishing positive health habits from an early age, school boards should be encouraged to follow a policy of required daily physical activity in primary schools. Evidence of specific benefit in students with learning disabilities remains less convincing.