Aim of the study: To evaluate executive functions in boys with attention deficit hyperactivity disorder (ADHD).

Material and methods: Twenty boys with ADHD (aged 7-11) participated in the study along with 20 healthy boys (aged 7-11) who comprised the control group. We used the Wisconsin Card Sorting Test (WCST) to analyze executive functions in the research and control group.

Results: The analysis of the results showed significant differences (p < 0.05) between the research and control group in the following WCST indicators: total mistakes (t = 2.386), percentage of mistakes (t = 2.288), perseverative answers (t = 2.405), percentage of perseverative answers (t = 2.311), and percentage of conceptual answers (t = –2.662). For the following WCST indicators the differences were significant at p < 0.01: perseverative mistakes (t = 2.854), percentage of perseverative mistakes (t = 2.850), non-perseverative mistakes (t = 4.282), percentage of non-perseverative mistakes (t = 4.112), finished categories (t = –3.056).

Conclusions: Analysis of the results shows that there are significant differences in functioning of executive functions between boys with and without ADHD measured by the WCST. Children with ADHD showed reduced ability to modify the course of thinking and to organize and control their cognitive activity.