The article examines local union approaches toward temporary agency work in Belgium and Germany. Heterogeneous plantlevel use of temporary work is explained by differences in collective bargaining, together with representation structures and rights for agency workers. Specifically, within a context providing effective rights for representation, the Belgian unions responded to firms' economic difficulties by improving the working conditions of agency workers through negotiating plant-level agreements that contributed to fostering equality between agency workers and regular workers. In contrast, agency work became instrumental in safeguarding the core workforce's employment in the German workplaces, where the representation rights were absent. As a result, the status of agency workers remained vulnerable.