Mainstreaming gender in political science education requires legislation, structures, instruments, and critical actors, not to mention a favourable political context for putting the issue on the agenda. These elements will be addressed in the context of Spain, with reference to the window of opportunity for mainstreaming gender in education opened up by the European Higher Education Area and the activity of gender equality institutions during the socialist Zapatero government. Following this opportunity, undergraduate gender and politics studies were introduced for the first time in Spanish universities, where they were formerly present mostly in interdisciplinary masters on gender. The process is fraught with resistances, along with opportunities. The case will be exemplified with a story of the development of the gender and politics network within the Spanish Political Science Association, its challenges and achievements, as well as a project leading to a pioneer textbook on Mainstreaming Gender in Political Science.