Numerous studies and articles on labor support have focused on the potential for improved labor and birth outcomes from supportive care during labor. Despite increased attention to labor support research, surprisingly little has been written about the theoretical underpinnings for intrapartum nursing care. This article explores Reva Rubin's framework and social support theory as a foundation for intrapartum nursing care. The most common features of social support provided the structure into which Rubin's descriptions of nursing care during labor and birth could be evaluated. Social support theory fit remarkably well, both with Rubin's views of the role of the perinatal nurse and with Rubin's observations of mothers' needs and feelings during childbirth. Combining these theoretical frameworks provides a perspective of intrapartum nursing practice that has not been previously considered in the published literature.