Early – or child – marriage (before age 18) may diminish women's ability to exercise agency, or their capacity to act upon their goals. Using a propensity score adjustment approach, we analyzed data from 2394 married women ages 35–49 years who participated in the 2006 Egypt Labor Market Panel Survey (ELMPS). We examined whether women's first marriage at age 18 or older was associated with their post-marital agency, measured in terms of their influence in family decisions, freedom of movement in public spaces, and unfavorable views about intimate partner violence against wives. In bivariate analyses, women's age at first marriage was positively associated with their decision-making and more equitable gender attitudes. However, once we controlled for selection into age-at-first-marriage groups, there were no significant differences between the two age-at-first-marriage groups in any dimension of women's agency. We examined the sensitivity of the non-significant age-at-first-marriage effects to possible violations of the strong ignorability assumption and the results did not alter our conclusions. The assumption that women's age at first marriage is a proxy for their post-marital agency, as defined here, warrants further study.