Many tout the benefits of collaborative environmental management as an alternative to centralized planning and command and control regulation, but the excitement over collaborative processes has not been matched by evidence that these processes actually improve the environment. The most crucial question in collaborative environmental management remains unanswered and often unasked: To what extent does collaboration lead to improved environmental outcomes? We know much about why collaboration is occurring and how collaborative processes and outputs vary. The primary goal of future research on collaborative environmental management should be to demonstrate whether collaboration improves environmental conditions more than traditional processes and newer market-based processes. Collaboration is not a panacea; it is a choice that policy makers and public managers should make based on evidence about expected outcomes.