OBJECTIVE: Early mother-infant interactions are impaired in the context of infant cleft lip and are associated with adverse child psychological outcomes, but the nature of these interaction difficulties is not yet fully understood. The aim of this study was to explore adult gaze behavior and cuteness perception, which are particularly important during early social exchanges, in response to infants with cleft lip, in order to investigate potential foundations for the interaction difficulties seen in this population. METHODS: Using an eye tracker, eye movements were recorded as adult participants viewed images of infant faces with and without cleft lip. Participants also rated each infant on a scale of cuteness. RESULTS: Participants fixated significantly longer on the mouths of infants with cleft lip, which occurred at the expense of fixation on eyes. Severity of cleft lip was associated with the strength of fixation bias, with participants looking even longer at the mouths of infants with the most severe clefts. Infants with cleft lip were rated as significantly less cute than unaffected infants. Men rated infants as less cute than women overall but gave particularly low ratings to infants with cleft lip. CONCLUSIONS: Results demonstrate that the limited disturbance in infant facial configuration of cleft lip can significantly alter adult gaze patterns and cuteness perception. Our findings could have important implications for early interactions and may help in the development of interventions to foster healthy development in infants with cleft lip.