Human African trypanosomiasis (HAT) is fatal if untreated and causes severe morbidity. In Tanzania HAT is caused by Trypanosoma b. rhodesiense. Trypanosomiasis in livestock is the major impediment to livestock farming and it limits the full potential of agricultural development in Tanzania. This study was undertaken in Kasulu district of Kigoma region, an area that is endemic for both human and animal trypanosomiasis. This study aimed to determine the prevalence of trypanosomiasis in domestic animals and the potential of these domestic animals as reservoirs of human infective trypanosomes. This study was undertaken in four villages namely Kagerankanda, Mvinza, Makere and Mvugwe. Eleven cattle samples (11%) of the 100 cattle sampled in the four villages were detected as positive by PCR using the ITS1 primers that identify trypanosomes to the level of species and subspecies. These were recognized as six Trypanosoma vivax (4%) and five Trypanosoma congolense forest type (3.33%). Cattle were more susceptible to trypanosome infection compared to other domestic animals like goats and dogs, because trypanosomes were not detected in these two species of domestic animals. Since Trypanosoma brucei species was not detected in this study, these results suggested that domestic animals that are kept in the study area do not harbour human infective trypanosomes and trypanosomiasis is prevalent in cattle.iii DECLARATION I, Jahashi Nzalawahe, do hereby declare to Senate of Sokoine University of Agricultur