Summary1. Conservation planning often relies on the use of surrogates for representing many aspects of biodiversity. Previous tests on the effectiveness of charismatic mammals as biodiversity surrogates have suffered from the lack of fine-resolution data and produced varied and contrasting results. 2. In this study, we used unique high-resolution data for more than 600 biodiversity features from the Maputaland-Pondoland-Albany global biodiversity hot spot to assess how the surrogacy effectiveness of the 'Big Five' charismatic mammal species could be improved. 3. We found that combining the 'Big Five' charismatic mammal species with well-known and surveyed taxonomic groups, such as birds, amphibians and reptiles, and habitat types, which can be mapped quickly and inexpensively, increases the representation of poorly surveyed taxonomic groups, such as endemic and threatened invertebrate and plant species, as well as other mammal species. In particular, habitat types were found to be an integral component of a successful surrogate strategy. Nevertheless, a broad cross-taxon surrogate group composed of the 'Big Five', birds, amphibians and reptiles, was found to be a more effective surrogate than habitat types on their own. Meanwhile, other taxonomic groups and habitat types were not effective surrogates for the 'Big Five' charismatic species. 4. As charismatic mammals have an important marketing value, they can be promoted to generate funding, which can then facilitate the implementation of conservation action and cover management costs, thereby indirectly benefiting other threatened biodiversity. 5. Synthesis and applications. While some geographic areas and taxa have been extensively studied, detailed information about the distributions of species is missing for much of the world. This study provides important information that can have operational relevance to prioritize areas for conservation action in areas of the world with poor data on biodiversity. We found that other taxa are not good surrogates for charismatic mammal species. We also found that habitat types are a necessary component of surrogacy strategies that cover plants and insects. Overall, a combination of habitat types and charismatic mammals, complemented with other well-known taxa (birds, amphibians and reptiles), provided the highest surrogacy effects.