Studies suggest that a substantial proportion of low-income working mothers experience work disruptions and parental stress related to child care, which may lead to increases in the risk of physical and psychological abuse and neglect of children. However, little research has examined the relationship between child care burden and the risk of child maltreatment among low-income working families. Using the Fragile Families and Child Wellbeing Study 3-year data, this study explores how child care burden is associated with the risk of child maltreatment (physical aggression, psychological aggression, and neglectful behavior) among low-income working mothers. We find that instability in child care arrangements is likely to increase mothers' physical and psychological aggression, while not having someone reliable for emergency child care is likely to increase mothers' neglectful behaviors. Findings also show that the risk of child maltreatment related to child care burden measures is more significant for single mothers than married mothers. Potential policy implications are discussed. (author abstract)