This meta-analysis of 68 studies (770 effect sizes) used random effects models to examine whether children's achievement differed depending on whether their mothers were employed. Four achievement outcomes were emphasized: formal tests of achievement and intellectual functioning, grades, and teacher ratings of cognitive competence. When all employment was compared with non-employment for combined and separate achievement outcomes without moderators, effects were non-significant. Small beneficial effects of part-time compared with full-time employment were apparent for all achievement outcomes combined and for each individual achievement outcome. Significant sample-level moderators of the associations between maternal employment and achievement for all outcomes combined included family structure, race/ethnicity, and socioeconomic status; associations were positive when samples were majority 1-parent families and mixed 1- and 2-parent families, racially/ethnically diverse or international in composition, and not middle-upper class. Analyses of child gender indicated more positive effects for girls. Children's age was a significant moderator for the outcome of intellectual functioning. The identification of sample-level moderators of the relationship between maternal employment and children's achievement highlights the importance of social context in understanding work-family linkages.