Children in the child welfare system experience high rates of exposure to potentially traumatic events, which are associated with significant impairments in safety, permanency, and well-being. However, child welfare systems have not routinely screened children for trauma, and little is known about such efforts. This paper describes five statewide and tribal projects to implement trauma screening for children in the child welfare system as part of broader, trauma informed care initiatives. Findings indicate that implementation strategies varied considerably but that screening generally resulted in identification of high rates of trauma exposure, trauma symptoms and service referrals. Further, screening was generally perceived favorably by child welfare workers and mental health professionals. However, wide variations were observed in the number of children screened, suggesting that more research is needed to identify optimal strategies. Lessons learned are described and recommendations made for implementing trauma screening in state or tribal child welfare systems.