The prior literature on the relationship between lead exposure and human behavior and the theoretical integration indicates that lead may be a distal predictor of crime and can promote crime in a variety of ways. Also, patterns of lead exposure may be related to community social disorganization and/or structural processes driven by powerful groups. The objective of this article was to summarize what is known about the association between lead exposure and human behavior and discuss the implications for criminology. The article begins with background information on lead sources and measurement, followed by the various impacts of lead exposure on humans. It then traces the potential linkage between the effects of lead exposure and traditional criminological theories. It posits that the link between lead exposure, aggression, delinquency, and crime is consistent with the traditional individual-level psychological based and aggregate-level sociological based theories that explain delinquent and criminal behavior and that differential lead exposure and treatment by neighborhood is congruent with theories of social disadvantage. The article concludes with a discussion of the implications of the lead and crime relationship and avenues for future criminological research. Figures, note, and references