Although many countries now have programs to lower the levels of lead in the environment, human exposure to Pb remains of concern to public health officials worldwide. The mechanisms of lead toxicity are still not fully understood, but recent findings have recognized the significance of the lead-induced impairment of the cell energy metabolism. This review outlines recent hypotheses and evidence on the role of nucleotide purines in erythrocyte metabolism regulation. It also describes the resynthesis and decomposition of purine nucleotides in erythrocytes, lead distribution in blood and its influence on purine conversion pathways and both glycolytic and pentosophosphate pathway enzymes in erythrocytes.