BACKGROUND: Platelet transfusion refractoriness can develop in patients after multiple transfusions of platelets. Once patients develop platelet refractoriness caused by immunological factors, HLA-matched platelet transfusion is required. However, there is no system to supply HLA-matched platelets in Korea. This study was performed to find way to promote the HLA-matched platelet supply in Korea. METHODS: The status of platelets supply in Korea and the frequency of platelet refractoriness in four university hospitals during 2005 were analyzed. It was obtained that the number of ordered and positive cases for the anti-platelet antibody, HLA antibody screening, and Panel Reactive Antibody test among inpatients of hematological malignancies. And the means to use the HLA-A, B data of unrelated bone marrow donors was searched. RESULTS: Platelet supply increased annually and totally 1,558,395 units were supplied in 2005, from Korean Red Cross blood centers. The frequency of platelet transfusion refractoriness was 12.4%, among them 10.4% showed anti-platelet or anti-HLA antibodies positive. A revision of the related law was required to use the HLA data of unrelated bone marrow donors. CONCLUSION: Immunological factors were observed in about 10% of patients with platelet transfusion refractoriness. HLA-matched platelet could be widely available if the HLA-typed donor registry is established in the Korean Red Cross after the revision of the related law.