BACKGROUND: Buffy coat method is one of the blood components processing methods widely used in many countries including Europe and Canada. For the first time in Korea, we evaluated the qualities of blood components manufactured by buffy coat method. METHODS: We collected 400 mL whole bloods using the quadruple top and bottom blood bag from thirty-five donors. Whole bloods were processed into leukoreduced RBC, leukoreduced pooled platelet, and 24 hr frozen plasma by the buffy coat method with blood bags and instruments of Fenwal and Fresenius. The qualities of each blood component were analyzed at each scheduled day, and compared with the standard guidelines of quality control in Korean Red Cross. RESULTS: The volume and hemoglobin of RBCs were lower than the standard guidelines. Comparing with the standard of apheresis platelets, leukoreduced pooled platelets showed higher total platelet yield with the median 3.70x10(11)/unit. Frozen plasma showed increased volume recovery than the standard guideline, but the activity of factor VIII at Day 35 was decreased to 0.66+/-0.14 IU/mL. CONCLUSION: We have found that the yields of pooled platelet and the frozen plasma processed by buffy coat method were higher than the standard guidelines. To introduce the buffy coat method to routine blood component separation process in Korea, further evaluations about the cost-effectiveness of buffy coat method are required.