Even very young children think about their own and others' behavior, including emotions. Such cognitions and emotions about the self and others convey information that is crucial to social interactions and relationships. The current study based on an integrated model of emotion processes and cognition in social information processing (SIP) aimed to explore students' emotional and behavioral responses in SIP choices, and their association with teacher-reported early school adjustment. Two-hundred and thirty pre-school and first-grade primary school students were interviewed using the Challenging Situations Task (CST). CST assessed students' emotional and behavioral responses to 12 unambiguous hypothetical peer provocation situations. Children's preschool and first-grade primary teachers rated children's early school adjustment with the Social Competence and Behavior Evaluation (SCBE-30) measure. The results revealed that children chose mainly sad and angry emotions and socially competent and passive behaviors. We found a relationship both between sad emotions and socially competent behavior choices, and between angry emotion and aggressive behavior choices. Sad emotions and aggressive behavior choices were the main predictors of school adjustment. Children's responses to peer provocation situations varied depending on how the children interpreted the situations. The results address the importance of children's SIP and school adjustment.