This study examines the impact of early abuse on the functioning and the 12-month treatment outcomes of 146 homeless addicted women who entered residential substance abuse treatment. Sixty-nine percent of the women reported exposure to childhood physical, sexual, or emotional abuse; the majority reported multiple forms of abuse. Comparisons of abused and nonabused women revealed significant differences in childhood, adolescent, and adult functioning, indicative of the pervasive detrimental effects of early abuse. Female survivors of childhood abuse did not improve in treatment as much as their nonabused peers in psychological functioning (p < .001), substance abuse (p < .01), or continuing trauma exposure (p < .01) . The findings suggest the importance of adapting models of residential substance abuse treatment to address concurrent issues related to trauma history. Additional research is needed to identify effective integrated treatment approaches for this population and to explore the independent and interconnected pathways linking trauma history and outcome.