Foster care is one of the most far-reaching interventions targeted at children who are abused or neglected by their parents, or who are engaged in anti-social behavior (Lindquist & Santavirta, 2014). The large number of children in foster care and the high cost of child welfare, makes the outcomes of former foster youth a trending topic in research. However, research that combines results on different extents (education, employment, wages, housing, mental health, substance abuse and criminality) is sparse. Using the PRISMA method, the outcomes of 32 original quantitative studies were compared. The studies were categorized into two groups reflecting on the child welfare orientation of the country: child protection vs. family service (Gilbert, Parton, & Skivenes, 2011). The results are clear as well as troubling. In both systems, children who leave care continue to struggle on all areas (education, employment, income, housing, health, substance abuse and criminal involvement) compared to their peers from the general population. A stable foster care placement, establishing a foothold in education and having a steady figure (mentor) who supports youth after they age out of care seem to be important factors to improve the outcomes. •Using the PRISMA method, the outcomes of 32 quantitative studies were compared.•The studies were categorized in child protection vs. family service systems.•Outcomes of foster youth are troubling on all domains, in both systems.•Having a steady homebase and establishing a foothold in education is most important.•Having a steady mentor, who gives support when needed is a protecting factor.