The magnesium, zinc, copper, iron and calcium level of plasma, erythrocytes, urine and hair in 50 children aged from 4 to 13 years with hyperactivity, were examined by AAS. The average concentration of all trace elements was lower compared with the control group--healthy children from Szczecin. The highest deficit was noted in hair. Our results show that it is necessary to supplement trace elements in children with hyperactivity.