We set two aims in the present study. First, we aimed to explore the impact of ADHD on the academic achievement and behaviour of children attending primary school, as reported by their teachers. Second, we investigated the independent influence of the three subtypes of ADHD on the child's functioning. Our research took place at the total of the six schools of a small provencial town of Peloponnese. We asked all the teachers of the first grade to fill in two coded questionnaires for each one of their pupils (N=290). The first questionnaire consisted of questions relevant to the children's adjustment to school, their academic achievement, their behaviour, their self-esteem level and the quality of their relationships with their schoolmates. The second questionnaire was composed of DSM's-IV criteria for ADHD. We analysed separately data concerning the three different subtypes of ADHD. Our results indicated that, ac-cording to their teachers, 10% of the pupils were found to meet the criteria for ADHD, Com-bined Type. These children appeared to face important difficulties in their adjustment to school in comparison to their peers. According to our results, the subtype which seemed to influence in particular academic achievement was ADHD, Predominately Inattentive Type. Given the negative impact of ADHD on several domains of the child's functioning, we suggest that intervention should be multi-level. Such an approach focuses on the improvement of the child's self-esteem and the increase of his / her motivation about learning. The techniques used should lead to the improvement of the child's ability for sustained attention and auto-regulation.