A total of 500 serum samples collected from cattle and buffaloes from various livestock farms in Punjab were analysed for brucella antigens. Out of these 500 sera, Rose Bengal Plate Test (RBPT) recorded 79(15.8%) positive. These RBPT positive samples were subjected to routine serum agglutination (SAT) and modified SAT (EDTA added) tests. The SAT showed 18(22.7%) positive, 42(53.1%) doubtful and 19(24%) negative samples, whereas modified SAT recorded 15(18.9%) positive, 28(35.4%) doubtful and 36(45.5%) negative samples. Results of modified SAT were observed to be more clear and easy to read than routine SAT. It was concluded that modified SAT may be used as an alternate to routine SAT in the diagnosis of brucellosis which may reduce the chances of cross reaction.