Background:Using a large population-based sample, this study aims to verify whether televiewing at 29 mo, a common early childhood pastime, is prospectively associated with school readiness at 65 mo. Methods: Participants are a prospective longitudinal cohort of 991 girls and 1,006 boys from the Quebec Longitudinal Study of Child Development with parent-reported data on weekly hours of televiewing at 29 mo of age. We conducted a series of ordinary least-squares regressions in which children's scores on direct child assessments of vocabulary, mathematical knowledge, and motor skills, as well as kindergarten teacher reports of socioemotional functioning, were linearly regressed on early televiewing. results: Every SD increase (1.2 h) in daily televiewing at 29 mo predicted decreases in receptive vocabulary, number knowledge scores, classroom engagement, and gross motor locomotion scores, as well as increases in the frequency of victimization by classmates. conclusion: Increases in total time watching television at 29 mo were associated with subsequent decreases in vocabulary and math skills, classroom engagement (which is largely determined by attention skills), victimization by classmates, and physical prowess at kindergarten. These prospective associations, independent of key potential confounders, suggest the need for better parental awareness and compliance with existing viewing recommendations put forth by the American Academy of Pediatrics (AAP).