Using ethnographic and survey data on low-income families residing in Boston, Chicago, and San Antonio, we examine the relationship between physical abuse, sexual abuse, and women’s patterns of union formation. Both sets of data suggest that women who have been physically or sexually abused are substantially less likely to be married or to be in stable long-term cohabiting relationships. The data also suggest that the timing and different forms of abuse may have distinctive associations with union formation. Women who have experienced abuse beginning in childhood, particularly sexual abuse, are less likely to be in sustained marriages or stable cohabiting relationships and instead are more likely to experience transitory unions: multiple short-term, mostly cohabiting unions with short intervals between them. Women who have not been abused in childhood but experience adult physical abuse, however, are less likely to be in either a marriage or a cohabiting union, long-term or transitory; and some have withdrawn from having relationships with men. The relevance of these findings for the decline of marriage among low-income women and men is discussed.