Objective: Parent-Child Interaction Therapy (PCIT) is an evidence-based treatment to reduce child disruptive behaviors and has been used for children with co-occurring posttraumatic stress symptoms (PTS). However, many families are faced with barriers that interfere with treatment completion. Engagement and attrition issues remain a continuous concern for families accessing needed services for youth. Furthermore, these issues are exacerbated for children in foster care.Methods: The present study explored differences in behavioral outcomes and graduation rates for children in foster care, (n = 206), non-foster care children with a history of trauma (n = 249), and non-foster care children without a history of trauma (n = 1,522) who participated in PCIT. Data was collected in community mental health agencies across the state of Oregon.Results: There was a significant decrease in caregiver reported disruptive behavior scores for all groups following PCIT. There were no significant differences found in graduation rates and average number of sessions attended between the groups; however, the graduation rate for this sample was low (17.8%).Conclusions: Results demonstrate that PCIT can be similarly effective in reducing problematic behaviors for children placed in foster care when compared to children not in foster care. Practical Implications: Given the low graduation rate, is imperative that we continue to investigate strategies to enhance treatment engagement and reduce barriers to services.