The relationship between maternal employment and the educational attainment of children is examined using data from the third wave of The Irish Longitudinal Study on Ageing. Because maternal employment is potentially endogenous with respect to child educational attainment, instrumental variable estimation is used. In this analysis, two sets of instruments are used based on whether the mother’s employment was affected by the Marriage Bar that was in place at that time in Ireland. A Marriage Bar is the requirement that women in certain jobs must leave that job when they marry. It is found that the probability that a child completes university is 1–3 percentage points lower for each additional year of maternal employment during the first 18 years of the child’s life.