Effects of early child care on children's functioning from 4 1/2 years through the end of 6th grade (M age=12.0 years) were examined in the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development (n=1,364). The results indicated that although parenting was a stronger and more consistent predictor of children's development than early child-care experience, higher quality care predicted higher vocabulary scores and more exposure to center care predicted more teacher-reported externalizing problems. Discussion focuses on mechanisms responsible for these effects, the potential collective consequences of small child-care effects, and the importance of ongoing follow-up at age 15. (Author abstract)