M.SC. DissertationA cross sectional study was conducted to determine seroprevalence of Brucella infection in cattle in urban and peri-urban areas of Sumbawanga Municipality. All 19 wards of the Municipality were involved in the study where 13 villages and 26 neighbourhoods (mitaa) were randomly selected. To identify the potential risk factors associated with spread and transmission of the disease, questionnaires were administered to the heads of randomly selected 108 households. Blood samples were also collected from 354 cattle of all breeds available in the study area and screened for Brucella antibodies by Rose Bengal Plate Test (RBPT). Results showed that 5 (1.4%) of the serum samples were positive. Confirmatory test of the RBPT positive sera was done using competitive Enzyme Linked Immunosorbent Assay (c-ELISA). Only, 0.8% (95% CI: 0.2-2.7 %) of the serum samples were c-ELISA positive and herd level seroprevalence was 2.8% (95% CI: 0.6-7.9 %). Analysis of potential risk factors related with the occurrence of Brucella antibody seropositivity in the study area showed no statistical significant relationship between any predictor variables and c-ELISA seropositivity. However, this study gives evidence that brucellosis is prevalent in Sumbawanga Municipality at much lower rate than the reported range (1-30%) in Tanzania. The evidence obtained in this study should be used for development of policy and control strategies to institute appropriate prevention, control and eradication measures of the disease; and carry out more epidemiological studies so as to characterize the Brucella organisms prevalent in the study area.