This article examines the relationship between management-based regulation and occupational health and safety through two case studies. The first describes how corporate occupational health and safety systems and standards were interpreted and implemented differently at different mine sites within the same company and examines the particular role of trust between workers and management in explaining variations in occupational health and safety performance. The second explores the difficulties of moving from a highly devolved system of responsibility to a more centralized approach, and the incapacity of externally mandated management-based regulation to change behavior at site level in the absence of a supportive workplace culture. The article argues that notwithstanding the heavy emphasis currently being placed on both internal (company-driven) and external (government-driven) management-based regulation, a commitment at corporate level does not necessarily percolate down to individual facilities where ritualistic responses or resistant subcultures may thwart effective change. The findings have important implications for the effectiveness of management-based regulation and meta-regulation more broadly.