An individual has a biological sex, which can be female, male, undetermined or unspecified. Through social and sexual conventions in society, an individual can develop his or her (or other) own gender representation which can refer to their biological sex or not and is interpreted by others according to the gender framework of a certain culture. Traditionally, we view gender as cultural or societal qualities that are related to biological sex. Theories of gender differences are based on a bipolar model of masculinity-femininity which is used to attribute certain behavioral and personal traits. Gender theory thus argues that a person is a product of culture, not nature, and it seeks to prove that masculinity and femininity traits are a consequence of a certain social and cultural context of each specific period. Gender differences can thus be viewed from different perspectives – from biological, psychological, biosocial perspective, etc. Understanding the exact nature of executive functions – as capacities of intentional and independent behavior that develop from early childhood together with the prefrontal cortex – in a school environment is limited due to lack of research which would examine these differences between the sexes. Executive functions can affect the formation of certain deficits and can directly or indirectly influence the students’ academic achievement as such. Findings in the research mostly highlight girls’ advantage in the verbal tasks and boys’ advantage in the spatial and working memory task. The main problem of my master’s thesis was the question of gender differences in executive functions. I predicted that there are major differences between the sexes in this area which I tested with measuring the following executive functions such as verbal fluency, working memory, switching ability, and inhibition in students (n = 101) in the third triad of elementary school, aged between 13 and 15 years. I used a test battery for measuring executive functions (Slana, Pečjak, and Repovš, 2017) with four tasks to measure these functions. I confirmed statistically significant differences (p < 0,01) between the sexes. Girls performed better in verbal fluency and working memory tasks, and boys in inhibition and switching tasks. I measured the connection between these four executive functions. Only lexical verbal fluency and working memory were connected statistically significantly (p < 0,01). I also examined the association between average final grades and the results of measured executive functions. The results of the correlational analysis showed the connection (p < 0,01) with all the measures of verbal fluency and working memory. Understanding the gender differences in executive functions has provided an insight into students' strengths on the theoretical level and indicated the potential for training less successful students in these functions for improving their academic performance in the practical level.