The author investigates gender differences in the impact of accumulated union experience on job satisfaction. Because there are fewer women than men in both public and private sector unions, and women are disproportionately underrepresented in union leadership, their collective bargaining power is not equivalent to that of men. As a result, women’s preferences for job characteristics and benefits may be overlooked, contributing to reduced job satisfaction as their tenure in the union increases. Using the National Longitudinal Survey of Youth (NLSY) panel data from 1979–2004, the author demonstrates that the accumulation of union experience negatively affects women’s job satisfaction more severely than it does men’s. This is particularly the case in private sector unions, in which women are more likely to be under-represented in both union membership and leadership positions.