Family reunification refers to the physical reunion of children with their biological families after they have been in family foster or group care settings. Research studies of family reunification indicate a wide range of reunification rates (13 to 70 percent) and foster care re-entry rates (10 to 33 percent). Reunified families must cope with many challenges, such as single-parent households, children who exhibit multiple behavioral problems, and difficulties associated with previous out-of-home placements. Because empirical knowledge about family reunification is still relatively limited, further research is recommended to explore issues in child and family development, child welfare service delivery, and training for child welfare service workers. Research priorities include establishing a national child welfare database; studying interactions among poverty, drug abuse, violence, and child abuse and neglect; conducting longitudinal studies of children in the child welfare system; examining family reunification as an expression of different levels of reconnectedness between child and family; evaluating the service delivery process and its impact on children and families; understanding child and family functioning after reunification; and identifying factors in the child, family, service delivery system, and environment that distinguish successful from unsuccessful reunification. 54 references and 1 figure