The objective was designed to assess the clinical efficiency of preventing febrile nonhemolytic transfusion reactions (FNHTR) with transfusion of leukocyte-depleted RBC and platelet concentrates. One hundred patients with cirrhosis of liver, gastric ulcer and cancer were selected to receive RBC concentrates with leukocyte filtration. Another group of 50 patients with liver necrosis, gastric ulcer and cancer were selected to receive non-filtered RBC concentrates. Two hundred and forty patients with acute or chronic leukemia, aplastic anemia, multiple myeloma, thrombocytopenia purpura, diabetes mellitus, cirrhosis of liver, upper gastrointestinal hemorrhage, severe hepatitis, burn and cancer post radioactive or chemical treatment were divided into two group with 120 patients in each one and selected randomly to receive platelet concentrates. The incidence rates of FNHTR in all patients were investigated. Results showed that there was no FNHTR in 100 transfusions with leukocyte-depleted RBC concentrates. Eight out of 50 patients with non-filtrated RBC concentrates showed FNHTR. The incidence of FNHTR was sixteen (16%) in non-filtrated transfusion. Twenty-five and 7 patients manifested FNHTR respectively in non-filtrated or filtrated platelets transfusions. The incidence of FNHTR was 20.83% and 5.83% respectively in non-filtrated or filtrated platelet transfusion. It is concluded that leukocyte-depleted RBC and platelet concentrates reduces FNH TR in blood transfusion.