This paper deals with the participation of worker representatives in workers' health inter-sector commissions (in Portuguese, CIST). Moreover, it approaches these professionals' strategies to defend the workers' right to health. In order to achieve these goals, we reviewed the literature to find the main ideas in this field, read conference reports and interviewed worker representatives who participate in the coordination of these commissions at the state level, especially in São Paulo, and in the national CIST. The study reveals the tension that is present in the relationship between citizenship and the market in the social construction of the accomplishment of workers' right to health. In relation to social control, the national conferences in the area and the National Health Council's resolution that stimulates councils to create CISTs enable the consolidation of the National Workers' Health Policy. However, the research shows the necessity of joint institutional actions in order to strengthen participation in the construction of the agenda, formulation, implementation and evaluation of worker's health public policies.