Children in the birth to 5 age range are disproportionately exposed to traumatic events relative to older children, but they are underrepresented in the trauma research literature as well as in the development and implementation of effective clinical treatments and in public policy initiatives to protect maltreated children. Children from ethnic minority groups and those living in poverty are particularly affected. This paper discusses the urgent need to address the needs of traumatized young children and their families through systematic research, clinical, and public policy initiatives, with specific attention to underserved groups. The paper reviews research findings on early childhood maltreatment and trauma, including the role of parental functioning, the intergenerational transmission of trauma and psychopathology, and protective contextual factors in young children's response to trauma exposure. We describe the therapeutic usefulness of a simultaneous treatment focus on current traumatic experiences and on the intergenerational transmission of relational patterns from parent to child. We conclude with a discussion of the implications of current knowledge about trauma exposure for clinical practice and public policy and with recommendations for future research.