In France, in the early 2000s, a group of several hundred Maghrebi-born workers engaged in a legal case against their former employer, the national railway company SNCF. For decades, they had been denied the same wages, promotions, retirement pay, and further benefits as their French colleagues. In 2018, they finally won their case at the Paris Court of Appeal, thus setting an important precedent in the struggle against institutional discrimination.Based on biographical interviews, mainly with SNCF workers from Morocco, this article analyses the structural and biographical conditions for engaging in this political and legal struggle and sheds light on, amongst other things, the importance of transnational dynamics in collective resistance within a postcolonial context. This article thus aims to contribute to the discussion on migrants’ political agency, and how it is hindered or fostered by the different policies of relevant institutions both in the country of residence as well as in the country of origin.