This study aimed to determine what youth characteristics were associated with emotional and behavioral problems exhibited within the first three months of placement in residential treatment centers (RTCs) in a sample of youth from 20 agencies in 13 states. Two primary research questions were addressed: 1) What characteristics were associated with behavior during the transition to care? 2) Were the characteristics associated with behavior during the transition the same for boys and girls? Data were drawn from the Time 1 phase of the longitudinal national Odyssey Project dataset developed by the Child Welfare League of America. Measures included an extensive child and family characteristics (CFC) form and the Achenbach Child Behavior Checklist (CBCL). The results revealed significant gender-specific patterns of associations between youth characteristics and behavior exhibited during the transition to RTC placement. Notably, a sexual abuse history was associated with Externalizing for girls and Internalizing for boys and entering on psychotropic medication was associated with Internalizing for girls and boys and Externalizing for boys only. Results suggest many avenues for refining practice. (Contains 5 tables and 1 footnote.)