Early social-emotional development occurs in the context of parenting, particularly via processes such as maternal emotion socialization and parent-child interactions. Results from structural equation modeling indicated that maternal contingent responsiveness partially mediated the relationship between maternal emotion socialization of toddlers (N = 119, ages 12-36 months) and toddlers' social-emotional competence. Effect size was strongest for the direct path between maternal emotion socialization and toddler social-emotional competence. Toddler age and maternal demographic risk status (covariates) predicted toddler competence. Study results extend the previous literature on early competencies by focusing on toddlers rather than preschool-aged children and by employing a contextual model in which both low-income mothers' emotion socialization and their contingent responsiveness predicted toddlers' competencies. (Contains 2 figures and 3 tables.)