The current study examined whether young children's executive functions and emotionality are related to childcare experiences and whether they work as mediators explaining the associations between childcare experiences and early school outcomes. Findings from a national sample of the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development (N = 990) revealed that centre-based care experiences and childcare quality positively predicted preschool children's executive functions, which then were linked to their academic skills and social skills in preschool and kindergarten years. Childcare hours were negatively related to executive functions. Further, childcare experiences did not predict children's emotionality, which was related to their social skills. Overall, childcare experiences, of higher quality, more structure and less hours, were modelled as predicting early school outcomes directly as well as indirectly through executive functioning.