Introduction: The right use of BLOOD is necessary because of the high cost of correct BLOOD screening, BLOOD grouping, and cross match. The purpose of this study is to evaluate the rate of the reserved and cross matched BLOOD before elective surgeries which were done in Bahman 22nd Hospital. It also aims at evaluating the standard guideline for ordering BLOOD.Materials and Methods: This is a retrospective study from 1380 to 1388 that evaluates evaluating 6145 files of the patients hospitalized in 22 Bahman 22nd Hospital for surgery during the years of 1380 to 1388. The elective operations include General surgery, Gynecology, orthopedic, ENT, Urology and Neurosurgery. The number of patients, the number of reserved and cross matched units and the number of transfused units was recorded for each group of patients collected in each groups. Finally, the number of reserved BLOOD units in that period of time and in each group was compared with the standard guideline. Also the number of transfused BLOOD units was evaluated. The ratio of cross matched to transfused BLOOD units lower than 2.5 was considered as standard. And The obtained data were analyzed, using with SPSS.Results: A total of 1557 BLOOD units of BLOOD were reserved for 772 patients.1305 units (66.47%) were cross matched, but just 126 units (8.1%) were transfused. The effective factors in increasing the possibility of transfusion were the ages<20 & >80 years old, Hb £ 12, the type of surgery and the surgeon. Although after the application of the guidelines in1385, there was 64.44% decrease in the rate of cross matching rate due to the decrease in the number of patients who were cross matched, but the average of cross matched units for each patient did not change. The total of C/T index of the hospital decreased from 14.1 to 3.7.Conclusion: The appropriate correct BLOOD reserving can decrease the unnecessary BLOOD reserves, lower the pressure on BLOOD banking centers and prevent BLOOD wastage.