In this longitudinal study we examined whether two components of effortful control, behavioral control, and executive function moderated the relation between temperament and conscience development. Temperament was assessed when participants were two years of age, and three temperament groups were formed: inhibited, exuberant, and low reactive. At 4.5 years of age, children's behavioral control and executive function were assessed. Moral behavior, emotionality during an empathy film, and false-belief understanding were measured at 5.5 years of age as components of conscience. Results indicate that inhibited children may benefit most from higher levels of effortful control. Inhibited children with higher levels of behavioral control performed better on false-belief understanding tasks whereas inhibited children who scored higher on executive function tests reported less emotional response to the evocative film. Finally, as a group, inhibited children exhibited more moral behavior than exuberant and low reactive children.