This article reviews research linking a number of temperamental vulnerabilities to the development of severe conduct problems in children. Also reviewed are 2 areas of research that focus on important developmental processes that could mediate the relation between temperament and conduct problems. These processes are the development of emotional regulatory abilities and the development of the affective components of conscience. Both of these processes have been associated with certain temperamental vulnerabilities, and they can both place a child at risk for the development of conduct problems. Importantly, these 2 processes may designate children who develop conduct problems through distinct causal pathways and, as a result, could help to explain some of the subtypes of antisocial youth reported in past research.