The Beck Self-Concept Inventory for Youth (BYI-S; Beck et al. in Manual for the Beck Youth Inventories of Emotional and Social Impairment, 2001) was administered to 100 adolescents (12–17 years old) who experienced sexual abuse. An iterated principal-factor analysis found that the BYI-S represented two highly correlated (r = .53) factors corresponding to the Self-Esteem and Competency dimensions that Steer, Kumar, Beck, and Beck (J Psychopathol Behav Assess 27:123–131, 2005) found with child psychiatric outpatients. Item analyses were used to derive two six-item subscales measuring Self-Esteem and Competency that had coefficient αs>.80. The Self-Concept total and subscale scores were differentially correlated with various psychosocial characteristics of the youth. Low Self-Esteem scores were associated with total number of posttraumatic symptoms and self-reported anger, whereas low Competency scores were related to externalizing behavior problems. The BYI-S was discussed as being a useful instrument for assessing the self-concepts of youth who have experienced sexual abuse.