This study was conducted to examine the effects of sports activities other than soccer on 10-15-year-old soccer players' motor skills. The sample included 146 registered soccer players in the U category (U10-U15) of the Turkish Football Federation's Aslantepe, Çeliktepe and Seyrantepe clubs. The players participated in this study on a voluntary basis. The players who participated in the study were divided into two age categories (10-12 and 13-15 years) and two groups, those who only played soccer (OS) and those involved in soccer and other sports (SAO). The study recorded the sociodemographic characteristics of the athletes, the sports they were interested in other than soccer, the weekly time they spent in different sports activities and the number of soccer training sessions they attended each week. The measurements for the study were completed in the first week of the preparation period at the beginning of the soccer season. All the participants were subjected to tests for speed, agility, horizontal jumping, endurance, and the motor tests that measured balance parameters, all of which are important for soccer. The study data were analyzed using SPSS 23.0 software. The study used the Kolmogorov-Smirnov test to determine whether the data had normal distributions. The parameters with normal distributions were analyzed using the t-test, while those without normal distributions were analyzed using the Mann-Whitney U test. The threshold for statistical significance was p<0.05. Analysis of the data showed that there were statistically significant (p<0.05) differences between the motor skills test results of the players in SAO group and those in the OS group. Thus, having children get interested in multiple sports at a young age instead of only one, and including forms of play that feature the fundamental skills of different sports in their training programs will positively contribute to the development of their motor skills and improve their performance.