In species management and conservation, surrogate species or groups of species can be used as proxies for broader sets of species when the number of species of concern is too great to allow each to be considered individually. However, these surrogate approaches are not applicable to all situations. In this article we discuss how the nature of the ecological system, the objectives and scale of management, and the level of available knowledge influence the decision about using a surrogate approach. We use species-area relations to define a “surrogate zone” in which the approach may be most effective. Using the Interior Columbia Basin of the northwestern United States as an example, we outline 10 steps that may enhance the effectiveness of surrogate approaches. Using a surrogate approach necessarily entails a trade-off between management tailored to individual species and less precise practices that may apply to a broader array of species. Ultimately, the use of a surrogate approach depends on the level of uncertainty that is acceptable in conducting management or conservation activities—in other words, “How good is good enough?”