We examine participation by women and men in legislatures in a critical case. Previous studies found that women often participate less than men in committee hearings and plenary debates. Yet these studies were conducted in cases where women held a fairly small share of seats and generally did not hold leadership positions or have seniority – factors expected to decrease participation. We use data from the Costa Rican Legislative Assembly (2010-2012) to assess whether women still participate less than men when placed in conditions of (near) institutional equality. Costa Rica has a successful 40% gender quota, a woman president, and no immediate reelection to the Assembly so all deputies lack seniority, thus many sex barriers have been broken in Costa Rican politics. In this apparently favorable environment, do women deputies participate equally with men? We answer this question using data from two standing committees, which offer variance on the percentage of women in attendance at each session. Empirical findings suggest that women participate as much as men in committee, even when the number of women on the committee is few. We also find that committee leaders are very active participants, which underscores the importance for women of obtaining committee leadership positions.