Climate change is posing an ever-increasing threat to wildlife around the world, making it a primary concern and driver of various changes including in habitat, species composition and disease transmission and, therefore important towards setting conservation priorities. We investigated the relative abundance and current and future distribution of small mammal species in the Selous ecosystem, Tanzania. We captured a total of 674 small mammal individuals belonging to 22 species, including 16 rodents, 2 insectivores, 3 carnivores and 1 primate. Acomys ngurui was the most dominant species, while Steatomys parvus was the rarest. Abundance was significantly different between habitats. Maxent models suggested that most of the current highly suitable small mammal habitats will shrink by the year 2050, and species will be forced to concentrate in a few areas within and outside the ecosystem. It is recommended that climate change impacts be properly considered when developing conservation areas' general management plans and planning for new protected areas.