A 65-year-old man underwent coronary artery bypass graft surgery at our tertiary care hospital. Perioperatively, he was transfused with four units of nonirradiated whole blood from first-degree relatives and discharged from the hospital at postoperative day seven. He presented six days later with fever, skin rash, elevated liver enzymes, and progressive pancytopenia. Elevated bilirubin levels and diarrhea were added to the clinical picture over the following days. Clinical findings and results of a skin biopsy specimen were consistent with transfusion-associated graft-versus-host disease. The patient died 20 days after transfusion.