The results obtained between 1981 and 1986 in a Dutch monitoring programme investigating the presence of arsenic, cadmium, lead and mercury in meat, livers and kidneys of sheep are presented. For the meat, livers and kidneys, the median values were 0.001, 0.003, and 0.007 mg/kg (fresh weight) for arsenic; 0.003, 0.054, and 0.098 mg/kg for cadmium; 0.04, 0.85, and 0.36 mg/kg for lead; and 0.001, 0.002, and 0.007 mg/kg for mercury. During the reported period, no clear trends were observed. The results are compared with the data from other countries. The mercury and arsenic concentrations in meat and organs may be regarded as low, but the levels of lead in livers are relatively high. The lead concentrations in livers showed seasonal fluctuations, the highest concentrations usually being found during the winter. Significant linear relationships were found between the concentrations in livers and kidneys for arsenic, cadmium and mercury. Tissue trace element levels were not related to the age of the investigated animals.