Relations among young preschoolers' social cognitive abilities, expression of emotions, and prosocial responses to others' emotions were investigated. 3 types of measures were employed with 27 2- and 3-year-olds: structured social cognitive, structured assessment of response to emotion, and observational coding of response to emotion displays. Results suggested that subjects' social cognitive acuity and differential responding to emotion have heretofore been underrated. Moreover, affective knowledge was significantly related to prosocial behavior in semistructured situations. Prevalent affect was related to expression of prosocial behavior (e. g., frequent expressions of anger were associated with low levels of affective knowledge and prosocial behavior). Thus this investigation benefited from broader conceptual definitions and contextualized measures.