Numerous studies on forgiveness in marriage and other romantic relationships have emerged since the first edition of this Handbook. Adopting the view that forgiveness provides the motivation for relationship repair but is distinct from relationship reconciliation, this chapter identifies major themes in recent research. These include documentation of a likely causal relation between forgiveness and relationship functioning, the role of self-forgiveness in understanding forgiveness in marriage, and the importance of contextual variables for the impact of forgiveness. Recognition that most religions emphasize forgiveness has led to study of how religion/spirituality are related to forgiveness in marriage. Importantly, research has identified conditions under which forgiveness can negatively impact marital functioning. The chapter identifies several issues for future research, including the need to study the history of relationship hurts when investigating transgressions, how forgiveness is communicated, and the implications of forgiveness for physical health. First-generation research on forgiveness in marriage has documented its correlates and emerging second-generation research has established a potential causal relation between forgiveness and its correlates. Third-generation research is now needed to identify mechanisms underlying the impact of forgiveness in marriage as well as the boundary conditions under which forgiveness in marriage is, and is not, beneficial.