Background: Developing control of attention helps infants to regulate their emotions, and individual differences in attention skills may shape how infants perceive and respond to their socio-emotional environments. This study examined whether the temperamental dimensions of self-regulation and negative emotionality relate to infants' attention skills and whether the emotional content of the attended stimulus affects this relation. Methods: Event-related potentials provided a neurophysiological index of attention (Nc) while 3 to 13-month-old infants viewed images of happy and fearful facial expressions. Temperament was measured via parent report using the Infant Behavior Questionnaire-Revised. Results: The peak latency of the Nc was slower for infants with lower regulatory capacity, independent of facial expression. The amplitude of the Nc over right fronto-central electrodes was related to both self-regulation and negative emotionality, but the effects differed by emotion: infants with better self-regulation had larger Nc responses to fearful faces, and infants scoring higher on negative emotionality had larger Nc responses to happy faces. These results are discussed in relation to the development of executive attention networks and their modulation by the amygdala. (Contains 4 figures.)