By analysing the first great railway strike in São Paulo (Brazil), this article aims to understand the role of the Companhia Paulista railway workers’ movement and its impact on labour relations in the São Paulo state. To that end, I have examined selected newspapers, the minutes of workers’ meetings, police investigations into the strike, and the reports of the Companhia Paulista's directors. Differing from the views of other historians who have tended to see the 1906 railway strike as a relatively inconsequential conflict about wages, I interpret it both as rooted in deeper grievances about labour conditions and as a starting point for a period of heightened militancy and changing labour-management relations.