The problem of the thesis is to identify the relationship of morphological characteristics and motor abilities with school performance. The thesis has studied the fourth and fifth grader pupils at four elementary schools from the suburbs of Ljubljana. The data were edited in Excel tables and analyzed using SPSS statistical programme. In the calculation of basic statistics there were frequencies, relative frequencies, average values and standard deviations which were calculated. For the variables that have been studied, minimum and maximum results were calculated as well as the Pearson coefficient to determine the connection between variables. Based on the results, we see that there is a statistically significant correlation between motor and morphological characteristics or abilities and school performance. The results of physical education classes and grades in certain subjects are therefore more affected by innate abilities than by hard-work.