Porcine brucellosis is a contagious bacterial zoonotic disease of public health importance worldwide caused by Brucella suis .This study aimed to estimate seroprevalence of brucellosis in pigs and potential risk factors for transmission. An epidemiological crosssectional study was carried out between December 2019 and March 2020 in Mpwapwa district of Dodoma region in Tanzania. A total of 23 villages and 144 pig-keeping households were randomly selected and included in the study. At the household level, two pigs were randomly sampled from herds with less than 10 where in households with more than 10 pigs three pigs were selected for blood sampling. A total of 349 serum samples were collected, (324 from smallholder pig farmers and 25 from the livestock training centres). Samples were transported to the microbiology laboratory at Sokoine University of Agriculture in a cold chain. Rose Bengal Plate Test (RBPT) was used to test for Brucella antibodies present in the sera. Out of the 349 pigs tested, 8 (2.3 %) were positive for Brucella antibodies, all positive sera were from eight different smallholder pig farms. There was lower seroprevalence in younger pigs (1.7 %) than older pigs (2.3%). In addition, females were more infected (3.8 %) than males (1%). However, the differences were not statistically significant between age and sex (P>0.05). Questionnaire survey results showed many pig farmers were not aware that pigs could get infected with brucellosis and transmit to human. Also there was significantly low knowledge on Brucella transmission among pig farmers. This study recommends educational campaigns in the study communities concerning with brucellosis transmission as well as further investigations on brucellosis to prevent its implications in public health and livestock production.