▪ Abstract Despite the fact that adoption is a common practice in the United States and in much of the world today, sociologists have devoted remarkably little attention to it. This review provides a rationale for much more extensive sociological research on adoption. It then summarizes the available empirical literature on who adopts children, and why, and on who relinquishes children for adoption, and why. Most adoptions have favorable outcomes for the members of the adoption triad (birth parents, adoptive parents, and adoptees). Yet the number of adoptions by nonrelatives has declined sharply since 1970, and only a small minority of women who have been treated for infertility have ever sought to adopt. These facts suggest that adoption may still have a stigma attached to it. Sociological research could illuminate whether such a stigma exists, and if so, what the causes and consequences of that stigma might be.