INTRODUCTION AND OBJECTIVE The developing brain of a child is extremely prone to damage resulting from exposure to harmful environmental factors, e.g. heavy metals. Intoxication of children's organisms with lead and cadmium affects their intellectual development. Even a relatively small amount of this metal in children's blood can lead to developmental dysfunctions. The aim of this study was to analyse the correlation between blood lead and cadmium levels in children with behaviour disorders and their functioning in the home. MATERIAL AND METHODS This survey-based study was conducted among 78 families with children diagnosed as having behaviour disorders. It was performed using the ADHD-Rating Scale-IV. To determine lead and cadmium levels the laboratory procedure was based on Stoppler and Brandt's method. RESULTS The mean blood lead level was 19.71 µg/l and the mean blood cadmium level was 0.215 µg/l. Higher blood lead levels in children correlates positively with incidences of hyperactive and impulsive behaviour in the home, as assessed by parents (p=0.048). Statistically significant effects of cadmium on children's behaviour were not noticed. CONCLUSIONS The effect of lead on the developing organism of a child has such behavioural consequences as attention disorders, hyperactivity and impulsive behaviour which, in turn, may interfere with children's functioning in the home. A negative effect of cadmium on the functioning of children with behaviour disorders in the home was not proved.