The relations between early emotional and behavioral problems in classroom situations and peer social competence were examined for a representative sample of urban Head Start children. Behavior problems were assessed within the context of routine peer, teacher, and structured learning classroom situations early in the preschool year. Two path models were tested: (a) direct effects of preschool situational problems on peer social competence at the end of preschool and (b) direct and indirect effects of preschool situational problems on peer social competence at the end of kindergarten, accounting for preschool peer social competence and child demographic variables. Early problems in peer and socially mediated learning situations consistently predicted lower peer social competence in preschool and kindergarten. Problems in preschool peer situations directly and indirectly predicted greater disruptive play at the end of kindergarten, and problems in structured learning situations predicted lower interactive play at both time points. Implications for policy and practice are discussed. (Contains 1 note, 2 tables, and 2 figures.)