Research indicates a link between maternal employment and children's risk of obesity, but little prior work has addressed maternal employment during children's infancy. This study examined the timing and intensity of early maternal employment and associations with children's later overweight and obesity in a sample of low-income families in low-income urban communities in the USA (n = 322). Logistic regression and propensity score models suggested that mothers' entry into employment when a child was 9-23 months old predicted a higher risk of child overweight/obesity at age 7 in comparison to both earlier entries and remaining out of the labour market for at least two years. This association was more pronounced with full-time work and existed mainly for children who remained in mother care or attended child care centres. Further work is necessary to determine mechanisms for this relationship, such as breastfeeding and nutrition. (Contains 1 note and 5 tables.)