Abstract:The aim of this study was to examine the effect of three months of teaching physical education on cognitive and psychomotor development in 9-11 year-old boys. 48 healthy students of both sexes (Age = 10, 8±0, 8 years; Height = 1, 45±0, 09cm; Body mass = 37, 9±9, 1kg) performed 4 cognitive tasks: cognitive flexibility (TMT A and B), inhibition (Flanker Test), selective attention (Barrage Test) and reaction time (computer task) and four psychomotor tasks: psychomotor mobilization (Skipping Rope Jump Test), eye-hand coordination (Basketball Wall Pass & Dart-throwing) and eye-leg coordination (Soccer Ball Wall Volley) were applied in the field and the lab. The sample was divided in three groups: group 1 (10 students), group 2 (22 students) and control group (16 students). The equipment and the measurements were taken immediately before and after three months of physical education program. The contents for instruction in physical education didn't allow an improvement in flanker test in G2. G1 undergone physical education and did physical activities outside of school shows a significant improvement in cognitive flexibility and inhibition. It has brought improvement for the G2 to the level of selective attention. CG has experienced an improvement in the reaction time, it allowed again a development of eye-leg coordination; of eye-arm coordination was determined in CG higher than the tow other groups. A correlation links the cognitive and the psychomotor skills. The results demonstrated that contents for instruction allowed a relative cognitive and psychomotor development, the updating of contents for instruction remains legitimate and urgent given all the changes in Tunisia.