Despite decades of growing engagement, there are still questions about the effectiveness of transnational private regulation in labour standards to improve employee welfare in global production networks. The literature shows that some improvementmay be expected in outcome standards, such as benefits, working time, health and safety issues, but not necessarily in process rights, such as freedom of association, collective bargaining and employment dialogue. Yet, workers need such rights if they are to have a voice and to participate in the organizational processes by which standards may be improved and compliance monitored. The authors of this article contend that the effectiveness of transnational private regulation in labour standards ultimately rests on workers’ capacity to act. The article is based on analysis of a cross-country and cross-sectoral data set from site-level surveys of 139 suppliers from Brazil and Kenya in the agricultural, manufacturing and service sectors. The analysis provides no evidence that either the presence of standards at a supplier’s site, or the awareness of such standards by workers employed at that site, have an impact on workers’ capacity to act. Moreover, the results provide only weak evidence that standards help workers gain influence over matters of relatively minor importance on the agenda of workplace cooperation.