While research on foster care placement stability has consistently shown differences between children placed with kin versus nonkin caregivers, scant research has focused on the experiences of foster parents raising children with severe behavior problems. The current study focused on differences in the perceptions of kin versus nonkin foster caregivers regarding their children with behavior problems and themselves. Social exchange theory was used as a theoretical framework to explore the relationship between these foster parent perceptions and the children’s placement stability. Participants were 259 kin and nonkin foster parents and their children who had been referred for Parent-Child Interaction Therapy (PCIT) services. Parents completed the Child Abuse Potential Inventory, the Child Behavior Checklist, the Parent Stress Inventory, and the Symptom Checklist. Information was also elicited concerning maltreatment history and patterns of treatment termination. Results of statistical analyses indicated few demographic differences between the kin and nonkin foster care dyads. Nonkin caregivers were more likely to report externalizing problem behaviors in their foster children, although the percentage of children within the clinical range did not vary between groups. Despite rating their foster children’s behavior as less severe, kin caregivers reported more parenting-related distress and rated higher on the Abuse Potential scale than did nonkin caregivers. Kin caregivers who reported high levels of parenting distress were more likely to persist in treatment than all nonkin caregivers and kin caregivers who ranked in the normal range for distress. A troubling finding indicated a relationship between elevated abuse potential and early treatment termination. The findings underscore the importance of considering the differences in perceived costs and benefits of raising foster children between kin and nonkin foster caregivers, especially concerning children with behavior problems and mental health treatment needs. Tables, references