Using data from the Korean Panel Study on Children in Out-of-Home Care, this study examined the impact of placement characteristics on aggressive behaviors among children in out-of-home care by placement type. The sample was divided into three groups based on placement type: institutional care (n = 118), group homes (n = 95), and foster care (n = 212). Results from hierarchical multiple regression analyses indicated that the length of stay in out-of-home care significantly influenced aggressive behaviors amongst children in institutional care, such that increased duration of out-of-home care decreased the level of aggressive behaviors. Perceptions of stigma/discrimination also significantly influenced aggressive behaviors displayed by children in institutional and foster care. Children with a higher perception of stigma/discrimination were more likely to exhibit severe aggressive behaviors than were their counterparts. On the other hand, placement characteristics had no significant influence on aggressive behaviors of children in group homes. The study findings suggest that children's mental health problems and disabilities should be considered during the placement procedure and interventions focusing on decreasing stigmatization should be developed and provided for children in out-of-home care. (C) 2016 Elsevier Ltd. All rights reserved.