Chlorinated hydrocarbon and polychlorinated biphenyl (PCB) concentrations were determined in adipose tissue from 34 infants, 14 children in the 2nd year of life, and 2 older children. The highest mean concentration detected during the first 2 years of life was for PCBs (0.67 ppm), followed by DDT (0.57 ppm), HCB (0.23 ppm), and HCH (0.15 ppm). Concentrations of HCB and PCB, which are especially characteristic of highly industrialised countries, were considerably higher in children of German mothers than in those of Turkish mothers. All single investigated values were lower than the mean values for adults in the Federal Republic of Germany, but many were still higher than mean concentrations for adults in other parts of the world. A breakdown into children with high mothers' milk intake and those with low intake showed a highly significant association with the quantity of mothers' milk consumed: the concentration of organohalogens in adipose tissue of children with high intake was significantly higher than in those with low intake. Two tasks urgently demand our attention: the development of further ways to reduce environmental sources of organohalogen contamination and the study of the possible pathogenetic effect of these organohalogens on the health of our children.