Five hundred people coming from the country-side, where a large number of cattle is bredeed, and 500 people coming from the city, were examined for the presence of humoral and cellular immunity to brucellosis with the standard agglutination test (Sat), anti-human globulin test (AHGT), Elisa test (Enzyme-Linked Immunoadsorbent Test) and IFN-gamma release in vitro. We found that Elisa test showed a higher sensitivity respect to the Sat and the AHGT test. In fact, with the Elisa test the seroprevalence was 10% for IgG, 9,4% for IgM and 1% for IgA in the rural country compared with that of the urban country which was 8,2%, 8,3% and 0,4% respectively. The Sat test and AHGT test, instead, showed a percentage of 91% and 87% with a titre < 20 from the rural country and a percentage of 96% and 98% from the urban area. Morover we noticed that the test based on the production of IFN gamma which appears to be an important mediator of cell-mediated immune response, agreed with serological tests