The present study examined associations between parents' levels of acculturation depressive symptoms, family support, and couple relationship quality with coparenting conflict. We also explored the effects of coparenting conflict on parenting and infant social development in a sample of low-income Mexican American (n=735) infants (age 9 months) and their parents. Results indicated that couple conflict was the strongest predictor of coparenting conflict. Coparenting conflict had a significant effect on mother-infant interaction and father engagement. The effects of coparenting on father caregiving varied by father's level of acculturation; when there is high coparenting conflict, more acculturated fathers engaged in more caregiving than less acculturated fathers. Coparenting conflict was not predictive of infant social development.