Freeze drying (FD) has gained more importance as a method for heat sensitive drugs, such as proteins, hormones, and vaccines, as it could be used for improving long-term stability on distribution and storage. The aim of this work was to prepare and characterize freeze dried powders of bovine serum albumin (BSA). BSA was lyophilized in aqueous dispersions alone, and with excipients such as lactose, sucrose, and mannitol. To evaluate FD process, tests such as particle size, residual moisture, yield, and BSA assay were performed at both, directly after preparation, as well as during different storage conditions. The best results were obtained by using sucrose of 2% concentration, and the best result for stability during storage was at temperature of 4 ͦ C. Our results confirmed that freeze-drying method is an efficient and suitable to obtained stable dried powders for heat sensitive pharmaceuticals such as albumin, and it could offer improved storage stability. In conclusion, successful lyophilization process must take into account two important factors, including the optimal formulation components and the understanding of critical parameters of the process.