Prosocial behavior is often thought to bring benefits to individuals and relationships. Do such benefits exist when prosocial behavior is costly for the individual, such as when people are sacrificing for their partner or relationship? Although different theoretical accounts would predict that sacrifice is either positively or negatively associated with personal and relational well-being, empirical work in this regard has been inconclusive. We conducted a meta-analytic synthesis of 82 data sets and 9,547 effect sizes (N = 32,053) to test the link between sacrifice and both personal and relationship well-being for both the individual who performs the sacrifice and their romantic partner. We examined four different facets of sacrifice (i.e., willingness to sacrifice, behavioral sacrifice, satisfaction with sacrifice, and costs of sacrifice). Results revealed that these facets were differently associated with well-being. Specifically, an individual's willingness to sacrifice was positively associated with their own personal and relationship well-being and with their partner's relationship well-being (.09 < rs < .27). However, behavioral sacrifice was negatively associated with own personal well-being (r = -.07). Satisfaction with sacrifice was positively associated with individual and partner well-being (.11 < rs < .43). Costs of sacrifice were negatively related to one's own personal and relationship well-being and to the partner's relationship well-being (-.10 < rs < -.26). Some moderators were also identified. We discuss the implications of these findings for research on prosocial behavior and relationships, address the implications of the methodologies used to study prosocial behavior, and suggest directions for future research. (PsycInfo Database Record (c) 2020 APA, all rights reserved).