This case study is about rewilding: efforts, arguments for and against, and progress to date. Rewilding is a radical restoration-based approach to ecosystem conservation and restoration that has garnered significant attention in the past decade. In this approach, living animals are introduced to areas where they may never have occurred, but where “similar” animals have become extinct. Proponents of rewilding argue that restoring conspecific or ecological proxy taxa to areas where major contributors to the food web have been extirpated has the potential to restore ecological and evolutionary processes important to biodiversity and ecosystem function. Rewilding proposals have been widely criticized due to the difficulty of predicting the ecological outcomes of introducing (or restoring) any species. Despite these criticisms, rewilding programs have made some progress. This case study highlights variables associated with the success of individual rewilding programs and examine these programs in light of the goals of rewilding and the concerns levied against it.