Hyperactivity with inattention is a disorder which starts before four years old, but it is not recognized until the child becomes a pupil. Manifestation persists during the entire childhood and expresses itself by such troubling elements as negativism, annoyance or fretting. A part of such characteristics could be recognized with all children, especially with those younger than three years old. The difference between hyperactive children with inattention and other fellows is a much higher degree and frequency of these characteristics` manifestation for them. When schooling starts, hyperactivity with inattention becomes more acute and ample by educational non-adaptation, tiredness and failure. Precocious hunting out and prophylaxis of this disorder could forestall the stress during the school adaptation and conduct disorder which could happen later in adolescence and youth.