We investigate whether the underrepresentation of experienced women politicians is attributable to voter preferences. Exploiting closely contested electorates in Australian state and territory elections, our regression discontinuity approach shows that parties are equally likely to nominate male and female incumbents to contest in elections. However, female incumbents are less likely to win, despite both having similar educational attainment and political experience. As less-experienced and younger challengers replace female incumbents at a higher rate than male incumbents, voters’ gender and age preferences impede the chances of women politicians ascending to leadership positions.