A study was carried out to characterise phenotypically the Ukerewe TSZ strain in order to know if it differs from the Bunda TSZ strain. Respondents from 46 households were interviewed on sources of income and food, number and species of livestock kept, ranking of livestock, usage of cattle, age at first calving, calving interval and lifetime number of calving. A total of 169 adult TSZ cattle were examined for coat colour pattern, and colours of coat, skin, muzzle, eyelid and hoof. Other traits that were examined are horn shape and sizes of udder, dewlap, testicle, navel-flap and prepuce. Physical body measurements namely body weight, heart girth, body length, withers height, horn length, ear length, muzzle circumference, hock circumference and tail length were taken for each cattle. The SPSS and SAS computer packages were used to analyse qualitative and quantitative data, respectively. Ukerewe TSZ cattle were observed to be significantly (p<0.05) heavier and calving earlier than Bunda TSZ cattle, whereas calving interval and lifetime number of calving revealed insignificant (p>0.05) differences between the two strains. Black colour occurred at significantly (p<0.05) higher frequency for the Ukerewe TSZ strain than for the Bunda TSZ strain. The Ukerewe TSZ strain was also found to have significantly (p<0.05) bigger heart girth and shorter horn length than the Bunda TSZ strain. The rest of the physical measurements and all external body appendages showed insignificant (p>0.05) differences between the two strains. With the exception of ear length and muzzle circumference, all measurements were positively and highly significantly (P<0.01) correlated with the body weight estimated from heart girth. Thus, the strains under the study differed remarkably in phenotype. Advanced characterisation of the strains using microsatellite DNA markers is recommended in order to establish if they could have a common origin.The Commission for Science and Technology together with the Ministry of Livestock Development and Fisheries