For a period of 24 weeks three sheep received hay contaminated with lead deposits from motor vehicle exhaust gases. The aim of this study was to compare the lead accumulation in different organs and tissues of two young sheep (I and II) consuming every day forage containing 8 and 73 ppM lead respectively (= milligrams per kg of dried substance). A third animal (III) was fed with forage containing 73 ppM Pb and received in addition water with 200 mg Pb/liter. The analyses made after slaughtering of the animals revealed a marked accumulation of lead in the liver, the bones of the pelvis, the kidneys, and the spleen. However, a notable proportion of lead is also excreted with the urine and feces. Histological studies revealed some changes in the hepatocytes of animals II and III. These lesions were more significant in animal III, which received the highest level of lead, than in animal II. It is possible that these alterations have been caused by toxic substances.