Background: Transfusion-associated graft-versus-host disease (TA-GVHD) is extremely rare compared to transplant-associated GVHD. Mortality in TA-GVHD approaches to 100%. We report six cases with TA-GVHD that were seen during 1994-2004 and discuss the clinical characteristics. Case Reports: Two patients were immunosuppressed, and 4 patients were immunocompetent. All 6 patients were transfused with non-irradiated blood products from relatives before TA-GVHD had occurred. Diagnosis of TA-GVHD in all patients was made based on characteristic clinical manifestations and laboratory findings. All patients died due to TA-GVHD-related complications such as progressive pancytopenia and liver dysfunctions. Conclusion: Our data shows that TA-GVHD is a serious complication of transfusion of blood products among relatives.