Combining work and family responsibilities is challenging when children have special needs, and mothers commonly make employment‐related adjustments. In this study, the authors examined associations between maternal work absence and child language impairment and behavior problems in preschool children. Questionnaire data at child age 3 years from 33,778 mothers participating in the prospective population‐based Norwegian Mother and Child Cohort Study were linked to national register data on employment and long‐term physician‐certified sick leave at child age 3–5 years. Mothers who reported having a child with language impairment had a consistently higher risk of not being employed and were at increased risk of taking long‐term sick leave at child age 5 years. Co‐occurring problems were associated with excess risk. Language impairments in preschool children, in particular when they are co‐occurring with behavior problems, are likely to have a range of negative short‐ and long‐term consequences for the financial and overall health and well‐being of mothers and their families.