The use of relocations, repatriations, and translocations as amphibian and reptile conservation strategies has received much debate. In the case of endangered species, their use may outweigh the potential negative consequences. We performed an experimental repatriation of the eastern massasauga (Sistrurus catenatus catenatus), which has experienced range-wide population declines and extirpations. The experiment included measures to minimize negative conspecific effects to the donor populations as well as inter-species effects on the release and donor sites. Snakes released during late July had lower mortality rates, larger home ranges, and gained more mass than snakes released in early September. The July release cohort also successfully reproduced, while no breeding activity was observed with September release snakes. Results of this study suggest that repatriation may be a viable method of restoring eastern massasauga populations. We hope the methods and conservation measures used in this experiment will serve as a template for future repatriations.