Background: Compared to residential care, family foster care is the preferable type of alternative care for neglected or abused children as it provides a familiar context that supports children's developmental needs.New foster families are needed to care for these children. Objective: This systematic review aims to provide a critical analysis of the literature, identifying factors that explain the intention to become and to continue as a foster family. This review was performed following the PRISMA checklist and guidelines, through a search conducted in the following databases (no restrictions were made): PsycArticles, PsycInfo, Psychology and Behavioral Sciences Collection, Academic Search Complete, ERIC, Scopus, and Web of Science. Study eligibility: The review includes empirical quantitative and/or qualitative studies in English, Portuguese and Spanish, with community and/or foster parents' samples and explores the factors for becoming and/or retention foster parents. Results: Forty-nine studies were included. The results revealed that the intention to become a foster parent is largely influenced by motivational factors, personal and family characteristics, individual values and beliefs, social context influences, and perceived familiarity with the child protection system. The retention of foster families is closely related to factors within the child protection system, personal or family characteristics, foster child characteristics, and placement challenges. The relationship with agencies and professional support stands out as the most important factors. Limitations and Implications: This review did not include studies focused on children with specific needs, and future research should consider the particular challenges of fostering this group. Practice implications of these findings for the recruitment, selection, and retention of foster families will be discussed.