This study used a British cohort ("n" = [approximately]13,000) to investigate the association between child care during infancy and later cognition while controlling for social selection and missing data. It was found that attending child care (informal or center based) at 9 months was positively associated with cognitive outcomes at age 3 years, but only for children of mothers with low education. These effects did not persist to ages 5 or 7 years. Early center-based care was associated with better cognitive outcomes than informal care at ages 3 and 5 years, but not at 7 years. Effect sizes were larger among children whose mother had low education. Propensity score matching and multiple imputation revealed significant findings undetected using regression and complete-case approaches. (Contains 3 tables.)