Nonmaternal care of infant children is increasingly common, but there is disagreement as to whether it is harmful for children. Using data from 9,185 children (5 years and older) who participated in the Children of the National Longitudinal Survey of Youth, the current study compared 2 groups: those for whom nonmaternal care was initiated in the first 3 years and those for whom it was not. Between-family comparisons showed that early nonmaternal care was associated with higher achievement and lower behavior problem scores in childhood and adolescence. However, within-family comparisons failed to detect differences between siblings who had different early nonmaternal care experiences. The study concludes that the timing of entry to nonmaternal care in the first 3 years has neither positive nor negative effects on children’s outcomes.