The rise of transnational nonstate certification programs has contributed to complex accountability relations surrounding efforts to hold companies accountable for their environmental and social impacts. Using the analytical lenses of internal and external accountability, we examine the Marine Stewardship Council (MSC)—a fisheries certification program—to assess how its decisions about goals, engagement of stakeholders, and accountability mechanisms have affected the controversies facing the program and how it has sought to address them. We reveal a misalignment between environmental groups and the MSC. Both seek to advance sustainable fisheries, and the market campaigns of environmental groups have supported certification. However, the MSC has provided these groups limited influence over its governance; it has responded to external demands for accountability by focusing on internal accountability, and reforming its assessment and objection procedures. Environmental groups have responded by working to decouple their campaigns from supporting the MSC. Tracing the consequences of this misalignment therefore highlights the need to assess rival processes such as market and information campaigns to understand attempts to hold nonstate certification programs to account.