As a way of laying the foundation for research in analyzing global gene expression patterns in Fisher 344 rat liver, the effects of lead toxicity on Fisher 344 rats were assessed using histopathology and tissue residues were measured for metal ions using ICP-MS. Accumulation of lead in blood, liver, kidney and bone marrow increased significantly in lead exposed groups. With the exception of kidney, the 90-days treatment groups showed markedly high levels of lead in blood, liver and marrow than the 30-days exposed groups. Potential interactions of calcium, iron and zinc and lead examined showed positive and negative correlations. Hepatic histopathology produced no evidence of necrosis nor changes in architecture of hepatocytes in the 0 ppm and 50 ppm for the 30-day duration of exposure in the case of the liver. In contrast, necrosis and alterations in the structure and disposition of the liver and kidney tissues were observed for the 500 ppm treatment group.