This study examined the severity of externalizing symptomology among adopted boys with preadoptive histories of child sexual abuse, physical abuse, neglect/abandonment, or no abuse. The study was based on data collected across a three-year period from parents who adopted children from Florida's child welfare system. The sample consisted of 1,136 adopted boys aged 6 to 18 years. In repeated cross-sectional multivariate analyses, the results revealed that adopted boys with preadoptive child sexual abuse were prone to significantly higher levels and clinically severe externalizing symptomotology as compared to adopted boys without such histories. The findings highlight the need for postadoption services and empirically validated interventions for families adopting boys with preadoptive child sexual abuse. (Contains 5 tables.)