Exposure to lead and nutritional inadequacy have been found to be related to learning and behavioral disorders in children. The bulk of the research on this relation is correlational, however, rendering the existence (and direction) of causality unknown. The treatment studies in this area generally have not included appropriate placebo controls or double-blind conditions. In addition, studies of lead exposure tend to exclude consideration of dietary factors in spite of the fact that competition between lead and trace minerals has been demonstrated. This article examines the cumulative effects of mineral insufficiency and exposure to lead.