This paper refers to a longitudinal research which took place between 1996-1998 in a provencial town of Peloponnese. Our first aim was to investigate the possibility for the nursery school educators to track down the ADHD children according to the diagnostic criteria of DSM-IV. Our second aim was to study the eventual difficulties of these children at the primary school. All the children(N=141) attending the seven nursery schools of this town, aged 4-5 ½ years old, participated in the first stage of this research. During the second stage, we searched at the primary school for those pupils who were presenting one of the three subtypes of ADHD at the nursery school (N=28). We administered the ADHD Test (J.Gilliam, 1995) to them and we compared their academic achievement, their behaviour and their self esteem level to the corresponding sectors of 28 children of a control group of the same age, who were not presenting any kind of problem at the first stage. We found out that there is high possibility for presence of ADHD for 50% of the children who were presenting ADHD at the nursery school. Moreover, their academic achievement is estimated to be below average, they often cause troubles with their behaviour and their self esteem level is low, according to the BASE inventory (S. Coopersmith & R. Gilberts, 1997). According to these results, we discuss the factors that influence the outcome of ADHD at the primary school, the possibilities of prevention and the necessity of early intervention at the cases of preschool ADHD children.