Ninety-nine 2-year-olds, out of a larger sample of 474 children, were classified as high (n = 49) or low (n = 50) in externalizing (aggressive/destructive) behaviors based on maternal reports assessed twice across a 2-month period. During a laboratory assessment, these toddlers participated in two empathy-eliciting tasks, from which affective, behavioral, and physiological measures were derived. Relations among measures of empathy were examined both within and across episodes and aggression groups. Analyses indicated that different indices of empathy were related to each other, both within and across empathy situations. In addition, aggressive children displayed more behaviors indicative of empathy than did nonaggressive children. Finally, a pattern of physiological responding to another's distress was evident across both groups of children, and some results indicated that greater physiological regulation was related to less empathy-related behavior. Results are discussed in terms of the developing nature of empathy and its changing association with both self-regulation and aggression.