Intimate partner relationship quality during the child-bearing years has implications for maternal health. The purpose of this study was to test whether partner satisfaction, partner conflict, and their interaction predicted maternal cardio-metabolic health at 12-months postpartum. Women were recruited in 5 U.S. sites. Partner conflict and satisfaction were measured at 6-months postpartum, and cardio-metabolic indicators (blood pressure, waist–hip ratio, glycosylated hemoglobin, total cholesterol:HDL ratio) were assessed at 6- and 12-months. Cardio-metabolic indices were scored continuously (CM risk) and using clinical risk cutoffs (CM scores). A significant conflict-by-satisfaction interaction emerged for the CM risk, b(SE) = .043 (.016), p = .006, and CM scores, b(SE)= .089 (.028), p = .002, such that when partner satisfaction was low, low partner conflict was associated with poorer postpartum cardio-metabolic health. This is the first study to examine close relationships and cardio-metabolic health during the child-bearing years, an issue warranting further attention.