Drawing on social and cultural capital theory, the study investigates the influences of social capital and cultural capital on the academic achievement of children in out-of-home care. We collected data from 494 children living in out-of-home services, including institutional care facilities, foster care homes, and group homes. To analyze the collected data, a multiple regression analysis method was used. In addition, the IV (instrumental-variables) estimation was utilized to rule out the possibility of reverse causality. The level of children`s social capital was measured through children`s relationships with parents and friends, parental monitoring, etc. The level of children`s cultural capital was measured by their cultural activities, such as going to museums, and playing musical instruments. Children`s personal characteristics and placement history in out-of-home services were used as control variables. We found that among personal characteristic variables, self-esteem, depression and anxiety, and delinquency affected the academic achievement of the children. Cultural capital, but not social capital, positively affected the level of academic achievement of the children. Based on the study results, implications for child welfare practice were discussed.