Using attachment theory as a framework, this paper examines how pregnant adolescents' experiences of physical maltreatment during childhood influence the subsequent mother-infant relationship in 203 low-income adolescents followed from the 3rd trimester of pregnancy through the 1st year of parenthood. The relation between physical maltreatment history and early difficulty in the mother-infant relationship was mediated by adolescents' evaluations of the relationship with their primary caretaker and the feelings they associated with motherhood measured prior to childbirth. In addition, a supportive romantic relationship during pregnancy acted as a protective factor by moderating the impact of maltreatment history on the quality of the subsequent mother-infant relationship. Findings support the importance of assessments and interventions that consider the social context and relational history of pregnant and parenting adolescents.