The Early Trauma Treatment Network (ETTN) will address the needs of traumatized young/preschool children by increasing access to evidence-based trauma treatment and raising the standard of care in key service systems. ETTN will build capacity and competence in early trauma services in pediatrics, home visiting, childcare, mental health, child welfare, and the military system. Young/preschool children are most vulnerable to trauma due to statistically higher exposure, developmental vulnerability, and dependence on parents or caregivers. Among military families, young children are at risk due to the impact of deployment and parental injury or death on family functioning. ETTN will address training and service gaps by activities that promote workforce development; create culturally informed products, training protocols and resources; and build cross-system linkages to promote collaboration among the key systems of care. ETTN is a collaborative of four leading national programs in early childhood trauma treatment, training, and dissemination. The lead agency is the UCSF Child Trauma Research Program, a multicultural program engaged in developing evidence-based treatments/interventions, training, clinical research, and direct service; the other sites are Child Violence Exposure Program at Louisiana State University Health Sciences Center, Child Witness to Violence Project at Boston Medical Center, and Infant Team at Tulane University Medical Center. All ETTN sites provide training in Child-Parent Psychotherapy (CPP), a manualized treatment for young children listed as evidence-based in the SAMHSA National Registry of Evidence-Based Programs and Practices. To enhance access and standards of care, ETTN will create products and conduct activities that increase agency readiness and promote sustainability of evidence-based and promising interventions; conduct 4 CPP Learning Co