This study utilized a population-based approach to examine the prevalence of children identified with disabilities in a large, urban Head Start program serving diverse preschool children living in poverty (N = 7,301). In addition, the study examined demographic differences in patterns of screening and identification for disability with respect to socioemotional and behavioral needs. Two administrative data systems were integrated for analysis: program enrollment and demographic records; and a mental health screening assessment database including all children enrolled within the Head Start program. Findings suggested that sex (male) and ethnicity (Hispanic) were associated with higher rates of identification for disability, including emotional/behavioral disability. In addition, of those children identified with an emotional/behavioral disability, the program-wide social-emotional screening tool showed greater rates of externalizing behavior problems compared to internalizing behavior problems. Implications for policy, future research, and practice within early childhood programs such as Head Start are discussed. (author abstract)