The study was aimed at finding out whether at the early school age the effectiveness of executive functions distinguishes children with ADHD from those of the control group. Besides, the aim was to check to what extent the use of diagnostic methods evaluating executive functions in children at the early school age is justified. The analysis comprised cognitive flexibility, sustained attention, interference control and planning ability. Those methods of neuropsychological evaluation were used which are mostly applied to characterize executive functions: Wisconsin Card Sorting Test, interference task based on the Stroop Interference Test, and tests of verbal fluency and Tower of London. The examined group consisted of 50 children aged 7-10: 25 children with hyperactivity of combined type and 25 children of the control group. Each group consisted of 23 boys and 2 girls. The average age in the criterial group was 8 years and 10 months (SD=10 months), whereas in the control group – 8 years and 6 months (SD=11 months). According to the obtained results, children with ADHD at early school age do not exhibit a wide spectrum of executive functions deficits, which is probably associated with immaturity of executive processes in all children of that age. The findings comprised only difficulties in inhibition of response, monitoring of activity, and ability of executive attention to intentional guidance of the mental effort depending on the task’s requirements. In investigations of children with ADHD at early school age the use of neuropsychological tests and trials designed for evaluation of executive functions is justified only in limited degree. They do not significantly distinguish between children with ADHD and children without this disorder, therefore the results may be mainly of descriptive, and not explanatory, value.