Stability study of biological products especially living bacterial vaccines plays an important role for determination of product changes in maintenance period and ensures safety, efficacy and maintenance of biological properties of the vaccines. So, the objective of this study was to establish stability and keeping quality of the local Brucella melitensis Rev-1 vaccine using different types of stabilizers in lyophilization process. A long-term stability study was carried out for four batches of reduced-dose Brucella melitensis Rev-1 vaccine manufactured by veterinary serum and vaccine research institute using four different stabilizers. These stabilizers were (A) sucrose and skimmed milk, (B and C) different concentrations of sucrose, sodium glutamate and gelatin, and (D) casein, sucrose and sodium glutamate. The quality control tests including colony forming unit, purity, dissociation and physicochemical tests on all batches until 12 months post- production were performed. The obtained results indicated that, in spite of collapse (shrinkage) of lyophilized cake in a number of bottles in batches prepared using stabilizer A, the brucella vaccine batches were stable and met the specification recommended by OIE 2012 for 12 months post-production in vaccine batches with stabilizers A and D.