Youth with posttraumatic stress disorder (PTSD) symptoms have significant difficulties regulating affective experiences; as a result, many engage in nonadaptive coping behaviors including deliberate self-harm (DSH). To identify youth with PTSD symptoms who may be most at risk for DSH, this study examined anxiety sensitivity (AS) as a moderator of the relationship between PTSD symptoms and DSH in a diverse sample of psychiatric inpatient youth with a history of potentially traumatic events (PTE). Participants (N = 50; 52.0% female; Mage = 15.1 years, SD = .51; 44% White) completed a test battery that included measures of DSH frequency, depression, AS and PTSD symptomatology. The proposed model accounted for 53.6% of variance in DSH, with PTSD symptoms being a significant predictor (sr2 = .11). The interaction of PTSD symptoms and AS accounted for an additional 4.5% of variance above and beyond covariates and main effects. Simple slopes revealed that the association between PTSD symptoms and DSH was significant for individuals scoring high (b = .25, SE = .06; t(50) = 3.83, p < .01) but not low (b = .03, SE = .10; t(50) = 0.30, p = .765) on the AS. Findings are consistent with theoretical and empirical work suggesting that DSH may be used to reduce emotional distress in the presence of maladaptive cognitive and emotional processes. (PsycINFO Database Record