['Because the controversy about the relation of foot morphology and foot function is still present, we find it surprising that there are no studies published dealing with motor skills and athletic performance in flat-footed school children. Our aim in this study was to determine if there is an association between the degree of foot flatness and several motor skills that are necessary for sport performance.', 'The feet of 218 children aged 11 to 15 years were scanned, and the arch index was determined. The value of the arch index was corrected for the influence of age, and then the entire sample was categorized into 4 groups according to the flatness of their feet. The children were tested for eccentric-concentric contraction and hopping on a Kistler force platform, speed-coordination polygon (Newtest system), balance (3 tests), toe flexion (textile crunching), tiptoe standing angle, and repetitive leg movements. Altogether, 17 measures of athletic performance were measured.', 'No significant correlations between the arch height and 17 motor skills were found. Categorizing the sample into 4 groups did not reveal any differences between the groups in athletic performance. Also, several multivariate analysis of variance sets of multiple independent variables referring to a particular motor ability were not found to be significant. The differences were not found even after comparing only the 2 extreme groups, meaning children with very low and children with very high arches.'] Is flat-footedness a disadvantage for athletic performance in children aged 11 to 15 years?