This study tested the potential mediating roles of various cognitive abilities in middle childhood (i.e., short-term memory [STM], sustained attention, and inhibitory control) in the associations between home learning environment in early childhood and child adjustment in multiple domains during early adolescence (i.e., internalizing and externalizing problems, language skills, and social competence), based on data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development (N = 1,364). Results demonstrated that the quality of home learning environment at 36 and 54 months was directly related to externalizing problems, social competence, and language skills at the 6th grade. Early home learning environment was also associated negatively with externalizing behavior problems at the 6th grade specifically via child sustained attention at 3rd grade. Additionally, the associations between early home learning environment and child language skills in early adolescence were mediated by STM, sustained attention, and inhibitory control in middle childhood. This study contributes to an increased specificity in the understanding of the roles of cognitive abilities in the far-reaching and comprehensive implications of early home learning environment for child later behavioral, social, and language development. Our findings suggest that training parents to appropriately build early home learning environment during the early years of life may yield benefits in the long run as it is a potential avenue to foster child later cognitive development and may ultimately facilitate child adaptation during the stressful, transitional stage of early adolescence. (PsycInfo Database Record (c) 2020 APA, all rights reserved).