The associations between mothers' part-time employment and mother well-being, parenting, and family functioning were examined using seven waves of the NICHD Study of Early Child Care and Youth Development data (N = 1,364), infancy through middle childhood. Concurrent comparisons were made between families in which mothers were employed part time and both those in which mothers were not employed and those in which mothers were employed full time. Using multivariate analysis of covariance with extensive controls, results indicated that mothers employed part time had fewer depressive symptoms during the infancy and preschool years and better self-reported health at most time points than did nonemployed mothers. Across the time span studied, mothers working part time tended to report less conflict between work and family than those working full time. During their children's preschool years, mothers employed part time exhibited more sensitive parenting than did other mothers, and at school age were more involved in school and provided more learning opportunities than mothers employed full time. Mothers employed part time reported doing a higher proportion of child care and housework than mothers employed full time. Part-time employment appears to have some benefits for mothers and families throughout the child rearing years.