Previous research identifies the increased exposure of birth children of foster carers to experiences of separation, grief, and loss due to the transient nature of foster care, but little is known about how birth children manage this loss. This paper reports findings from a qualitative study that examined the retrospective experiences of 15 adult birth children of foster carers (aged between 18 and 28 years) in Ireland. Findings suggest that birth children experience grief and loss when foster children leave their families. They report experiencing a range of emotional responses such as guilt, blame, and sadness. A reluctance to discuss their emotional responses with either their parents or foster care professionals was also reported. Instead, birth children developed strategies to manage the loss, such as distancing themselves from the foster care process. The study highlights the importance of social workers and foster carers explaining to birth children why foster children are leaving and, where possible, maintaining contact between birth children and foster children. Additionally, findings indicate the need for birth children to have safe nonjudgmental spaces to discuss their emotional reactions to loss.