This study aimed at comparing the effect of two blood taking methods namely venipuncture and saline lock on the results of blood routine tests obtained from the CCU hospitalized patients conducted non randomly and unicentral without control group on a number of 80 CCU hospitalized patients in pedagogical hospital in Zahedan. The criteria for entering the study included that the patients age must range from 35 to 70, they are required to do CCU routine tests according to the physicians’ order. They should not have any deformity on upper limbs. The exclusion criteria included lack of having suitable vein for catheter insertion and saline lock fixation and failure in taking blood from saline lock for the first time sampling. The intended interventions were conducted after the physician’s visit from 8 to 11 in the morning through blocking a tourniquet and after removing 0.5 ml of blood in the dead space of saline lock. The amount of five ml of blood was considered for the intended test. The same amount of blood was taken ordinarily from the opposite hand simultaneously as a control. The amount of CBC , ESR , CRP, BUN, Cr, Na, K, TG, Cholesterol, FBS , CPK, CKmb, LDH, PT, PT were compared