The aim of this study consists of the analysis of certain differences in motor skills of male children who are sedentary and in the age group of 9-14, in relation to the biological maturity. 522 sedentary male children from various parts of Turkey participated in this study. Body height and body weight measurements were taken from the participants in order to determine their body mass indexes while finger grip strength, hand grip strength, standing long jump test, med ball throwing test, flexibility test (sit-reach), active jump test, anaerobic power test, 20 meter sprint, pro-agility test and 20 meter shuttle run tests were applied in order to determine certain motor skill levels of the participants. The motor skill levels of the participants were noticed to show significant differences generally based on the age groups (p<0.05). The biological maturity levels of the participants were determined to be a factor which significantly affected the performances of the participants in aerobic durability, right and left hand grip strength, right and left finger grip strength, flexibility, med ball throwing, standing long jump and sargent jump (p<0.05). On the other hand, the findings regarding the speed performances were observed to show conflicting results, therefore biological maturity was found not to be a determinant over the 20 meter speed performance. As a result, certain motor skill differences in relation with biological maturity were observed in the sedentary male students of the 9-14 age group. Therefore, it can be stated that in order to reach reliable results, considering the biological maturity levels of the students along with the obtained test scores in sports skills qualification tests can be beneficial.