Introduction: During the storage of transfusion blood, it can undergo cellular changes that could be the reason behind the risk of using prolonged stored blood. Therefore, it’s important to monitor the cellular changes that may reduce its survival and function. The objective is to access the morphological and functional changes occur in blood stored for transfusion at GMERS Medical College, Gandhinagar. Methods: A single center, prospective study design involving 51 randomly selected donor blood units in citrate phosphate dextrose adenine (CPDA-1) anticoagulant was employed; cellular changes were evaluated for 35 days. The changes were tested using the Haematology analyzer (Hemax 330). Results were regarded as significant at P<0.05. Results were presented in tables and charts. Results: At the end of the 35 days blood storage at blood bank conditions, WBC, & platelets counts decreased significantly (P=0.0004 & <0.0001). The Hb, RDW, MCV & HCT increased significantly (P <0.0001, <0.0001, <0.0001, <0.0001) Conclusion: Platelets, WBC and indices are significantly altered in stored blood especially when stored over two weeks based on most of the cellular components analyzed in this study. The study, therefore, recommends the utilization of fresh blood to avoid the adverse outcome of cellular changes of reserved blood.