Strength-based assessment of behaviors in preschool children provides evidence of emotional and behavioral skills in children, rather than focusing primarily on weaknesses identified by deficit-based assessments. The Preschool Behavioral and Emotional Rating Scales (PreBERS) is a normative assessment of emotional and behavioral strengths in preschool children. The PreBERS has well-established reliability and validity for typically developing children as well as children with identified special education needs, but this has not yet been established for children in Head Start programs, who tend to be at high risk for development of emotional and behavioral concerns. This study explores the factorial validity of the PreBERS scores for a large sample of children participating in Head Start programs around the United States. Results not only confirm the fit of the four-factor model of the PreBERS for this population, but also demonstrate the application of a bifactor model to the structure of the PreBERS which, in turn, allows for the computation of model-based reliability estimates for the four subscales (Emotional Regulation, School Readiness, Social Confidence, Family Involvement) and overall strength index score. The implications suggest that the PreBERS items are reliable scores that can be used to identify behavioral strengths in preschool children in Head Start, and support planning of interventions to selectively address component skills to promote child social and academic success.