The methodology for assessing the impact of lead on farm animals under chronic intake with the ration is based on the lead metabolism and mechanism of biological action. When assessing the impact of lead, the environmental and epizootic situations, as well as the health of farm animals at different levels of biological organization: cell – organ – organism – population are studied. According to the results of environmental and epizootic studies the acting and concomitant factors, the scope of pollution, levels of contamination of soil, drinking water and feeds, the duration of lead intake with the ration into farm animal are determined. Under assessment of the animals health, along with the biomarkers “exposure” and “effect”, generally established clinical, hematological and biochemical indicators are determined. If necessary, the morphological state of organs and tissues (liver, kidneys, spleen, bone marrow, heart, lungs) is studied. The presented methodology will allow us to more correctly assessing the impact of lead on farm animals in environmentally disadvantaged regions.