Does the merit-based selection process help to reduce gender discrimination in public administrations? To answer this question, we conducted an in-depth case study in Mexico and built two original databases for analysis. First, we measure vertical and horizontal discrimination, and second, we examine merit-based competitions for access to upper management levels of the Mexican public administration to explore their role in reproducing gender discrimination. We find the existence of both vertical and horizontal segregation, and the analysis of merit-based competition results shows that women have difficulty winning competitions for the highest hierarchical levels and traditionally male sectors. Based on these findings, we explore the role of merit-based competitions in reproducing gender discrimination. Finally, we urge for the inclusion of a gender perspective in public service reforms in Latin America.