A study on the prevalence of hydatidosis in cattle, goats and sheep was carried out in Ngorongoro district of Arusha region, Tanzania. A 4-years data records from four slaughter slabs were retrieved and analysed. In addition, meat inspection was done in the same slaughter slabs for nine months and 64 households were interviewed to assess the community awareness on hydatidosis. Results showed the overall prevalence of hydatidosis to be 47.9%. Species prevalence of 48.7%, 34.7% and 63.8% in cattle, goats and sheep respectively was recorded. Of 174 cysts examined in cattle, 37 (21.3%) were fertile, 126 (72.4%) were sterile and 11 (6.3%) were calcified. Out of 215 goats and 67 sheep cysts examined, 52 (24.7%) and 26 (38.8%) were fertile, 138 (64.2%) and 38 (56.7%) were sterile, 24 (11.2%) and 3 (4.5%) were calcified respectively. The higher percentage of fertile hydatid cysts in sheep and goats coupled with the practice of backyard slaughter of sheep and goats suggests that, these animals could be important intermediate hosts for the maintenance of the domestic life cycle of E. granulosus in the locality. Questionnaire survey revealed that 17.2% of the respondents were aware of hydatidosis but non of them were knowledgeable on its transmission. Up to 84.4% of the respondents had domestic ruminants and donkeys, while 89.1% had dogs. Of the households with dogs, only 19.3% had their dogs dewormed at least once in life time. Most of the households (87.7%) had their dogs managed freely and 77.2% of the respondents reported school children to be the closest friends of dogs in the family. The prevalence of E. granulosus infection in wildlife and the possible relationship of the domestic cycle to the sylvatic cycle operating in the same area are unknown and need to be studied.