Synchronous interactions are an important indicator of parent-child relationship quality with positive implications for child development. Latina adolescent mothers face several demographic challenges that place them at risk for less synchronous interactions. To identify factors that may facilitate more optimal parent-child relationships in this population, our study examined maternal sensitivity and children's behavioral styles as joint predictors of dyadic synchrony among young Latina mothers and their toddlers. Mother-toddler dyads (N = 170) were observed interacting across different tasks, and toddlers' behavior was observed during the administration of a developmental test. Results of multivariate regressions revealed additive effects of maternal sensitivity and child behavioral styles (i.e., dysregulation and positive attentional control). Maternal sensitivity related to higher dyadic synchrony for the entire sample. Positive attentional control was related to higher dyadic synchrony for mother-daughter dyads only. Although no gender differences in dyadic synchrony or the behavior style variables emerged, the relative contribution of maternal and child factors differed by child gender, suggesting that mothers may have responded differently to similar behavior and affect displayed by boys and girls. The findings provide insights regarding factors that contribute to dyadic synchrony in this understudied population and emphasize the need to consider child gender when studying parent-child interactions in young Latina families.