The transformation and fragmentation of natural land are considered to be major drivers of biodiversity loss and local extinctions. In this study we compare medium-to-large mammal diversity on rangeland, game farms and natural land within the Little Karoo, South Africa. Mammal diversity was assessed using camera traps set up at 141 sites, and compared across the three land-use types. There were no significant differences in mammal diversity across land-use types, although rangelands typically supported fewer species. Game farms had similar species richness to natural areas, suggesting that the introduction of large ungulate species and the erection of game-proof fencing has had little impact on mammal diversity to date. Importantly, our results suggest that land used for low-intensity grazing by cattle (Bos taurus) can support similar mammalian species richness to natural areas, which indicates a high level of compatibility between current economic activities and biodiversity conservation in this area. Although specific to the Little Karoo, our findings can inform management and conservation decision-making on a broader scale, as they support evidence of the biodiversity value of economically active land.