Blood was collected from 71 tsessebe antelope and ticks from 12 of these animals, in the Vaalbos National Park. The samples were collected when the animals were relocated to a new park as a result of the deproclamation of Vaalbos National Park. DNA was extracted from the blood samples and the V4 hypervariable region of the 18S rRNA gene of any piroplasm parasites present was amplified by PCR. The RLB hybridisation technique was used to identify piroplasm parasites. Theileria spp. were identified and full-length 18S rRNA genes were amplified, cloned and sequenced. The results indicated the presence of novel Theileria spp. phylogenetically very closely related to both Theileria sp. (sable) and Theileria separate. The ticks collected were all Rhipicephalus evertsi evertsi, which has been shown to be capable of acting as a vector for Theileria spp. All animals appeared to be in good health at the time of sampling and after relocation. It is thus possible that, as with several other wildlife species, the Theileria spp. identified here do not cause disease under normal circumstances and that a situation of endemic stability exists. Once the host is under any form of stress, however, overt clinical disease may well become evident. The significance of these Theileria spp. should not be underestimated, and care should be taken not to transmit the organisms into new areas. More research will need to be conducted to determine the exact clinical significance of these findings and the role of Rhipicephalus evertsi evertsi as a potential vector for these Theileria spp. Copyright / Dissertation (MSc)--University of Pretoria, 2008. / Veterinary Tropical Diseases / unrestricted