Identified first-grade children who exhibited 4 different behavior problem profiles from an initial sample of 754: aggressive-withdrawn (n = 63.8%) aggressive only (n = 165, 22%), withdrawn only (n = 94, 12%), and nonproblem (n = 432, 57%). Group comparisons revealed that children who became aggressive-withdrawn in first grade exhibited deficits in attention and social skills in kindergarten. Furthermore, these kindergarten deficits contributed to the emergence of their aggressive-withdrawn behavior problems in first grade, after accounting for kindergarten levels of aggressive and withdrawn behaviors. In later grades, aggressive-withdrawn first-grade children were more likely than children in any other group to demonstrate poor peer relations and poor academic performance. In addition, kindergarten skill deficits added to first-grade aggressive and withdrawn behavior problems to predict third-grade social and academic adjustment difficulties. The results document the key role of early inattention and social skill deficits in the prediction of aggressive-withdrawn problem profiles, validate the significance of this problem profile at school entry, and identify potential developmental mechanisms that have implications for preventive interventions.