AbstractDevelopmental trauma disorder (DTD) and posttraumatic stress disorder (PTSD) have been found to have both shared and unique traumatic antecedents. The present study was an independent replication, with the DTD Structured Interview and the Traumatic Events Screening Instrument administered to 271 children in mental health treatment in six U.S. sites. On an unadjusted basis, DTD (27.3% prevalence, N = 74) and PTSD (40.2% prevalence, N = 109) both were associated with traumatic physical assault or abuse, family violence, emotional abuse, caregiver separation or impairment, and polyvictimization. After controlling for PTSD, DTD was associated emotional abuse, OR = 2.9, 95% CI [1.19, 6.95], and traumatic separation from a primary caregiver, OR = 2.2, 95% CI [1.04. 4.60], both of which also were associated with caregiver impairment, physical assault/abuse, and witnessing family/community violence. Three traumatic antecedents associated with PTSD were not associated with DTD: noninterpersonal trauma, sexual trauma, and traumatic loss. Children exposed to both traumatic victimization and attachment trauma (36.2%) or attachment trauma alone (32.5%) were more likely than children exposed only to victimization (17.5%) or those with no history of victimization or attachment trauma (8.1%) to meet the symptom criteria for DTD, χ²(3, N = 271) = 17.68, p < .001. Study findings replicate and extend prior DTD field trial study results, showing that, although PTSD and DTD share traumatic antecedents, DTD is uniquely associated with traumatic emotional abuse and caregiver separation. Further research is needed to examine how specific trauma types contribute to the risk, course, and severity of DTD.