Endothelial cell cultures were established from several wild African mammalian species. Long-term cultures were established from three ruminants, sable antelope (Hippotragus niger), buffalo (Syncerus caffer), and eland (Tragelaphus oryx), and from an omnivore, the bush-pig (Potamochoerus porcus). Cowdria ruminantium was isolated from plasma of clinically affected animals in these four cell lines and in bovine endothelial cells used routinely for C. ruminantium propagation. Nineteen different strains of C. ruminantium from Africa and the Caribbean region were grown and maintained in these cell lines and their growth was comparable with growth in the bovine endothelial cells. The role of sable antelope, eland, and bushpigs in the epidemiology of heartwater is unknown. However, these results extend the number of cell lines that can be used to isolate and grow C. ruminantium.