Although preterm infants are at risk for social deficits, interventions to improve mother–infant interaction in the neonatal intensive care unit (NICU) are not part of standard care (SC). Study participants were a subset from a randomized controlled trial of a new intervention for premature infants, the Family Nurture Intervention (FNI), designed to help mothers and infants establish an emotional connection. At infants’ 4 months corrected age, mother–infant face-to-face interaction was filmed and coded on a 1-s time base for mother touch, infant vocal affect, mother gaze, and infant gaze. Time-series models assessed self- and interactive contingency. Comparing FNI to SC dyads, FNI mothers showed more touch and calmer touch patterns, and FNI infants showed more angry-protest but less cry. In maternal touch self-contingency, FNI mothers were more likely to sustain positive touch and to repair moments of negative touch by transitioning to positive touch. In maternal touch interactive contingency, when infants looked at mothers, FNI mothers were likely to respond with more positive touch. In infant vocal affect self-contingency, FNI infants were more likely to sustain positive vocal affect and to transition from negative to positive vocal affect. In maternal gaze interactive contingency, following infants’ looking at mother, FNI mothers of male infants were more likely to look at their sons. In maternal gaze self-contingency, following mothers’ looking away, FNI mothers of male infants were more likely to look at their sons. Documentation of positive effects of the FNI for 4-month mother–infant face-to-face communication is useful clinically and has important implications for an improved developmental trajectory of these infants.