Background: Interest in the development of a 6-7-year-old child derives among other things from the necessity to evaluate child's readiness to take up a regular educational process. Physical development and physical fitness of the child are components of school maturity.The purpose of the study was to show similarities and differences in the level of physical development and fitness of children attending school and pre-school institutions in the years 2005-2009 in Gdansk.Material/Methods: 15,578 children (8,006 boys and 7,572 girls) from Gdansk were subject to research in the years 2005-2009. The measurements of the height, body mass and 5 skin folds were carried out. BMI and %BF were calculated. To determine the physical fitness level, the following tests were applied: sit and reach, standing broad jump, sit-ups and a 3-min step-test.Results: In pre-schools children higher values of body height were observed in the investigated period (2005-2009) but, at the same time, there were no differences in body mass between children from pre-schools and schools. Nor did the children differ in the amount of fat deposition. In the fitness level the biggest differences between the results achieved by children from schools and pre-schools were noted in the test of standing broad jump on both feet. Both boys and girls from pre-schools got higher scores in this test and their post-effort HR was lower in comparison with their peers from schools.Conclusions: Differences in the level of physical fitness, especially its manifestations depending on everyday physical activity, reflect well on conditions created for children in pre-schools.