Acute GVHD is a rare complication after liver transplantation that has a high mortality rate. We experienced an infant case complicated with acute GVHD. An 8-month-old infant with biliary atresia underwent LDLT with a graft obtained from his mother. Their HLAs showed a donor-dominant one-way match, not at HLA-DR but at HLA-A, HLA-B, and HLA-C (recipient; A 31/33, B 51/54, C 1/14, DR 9/11, donor; A 31/-, B 51/-, C 14/-, DR 8/11). The patient exhibited a high fever, skin rash, and diarrhea, and was diagnosed with acute GVHD based on the blood chimerism test. Despite immunosuppression treatment with prednisolone and tacrolimus, plasma exchange, blood transfusion including cord blood transplantation, and antibiotics, the child died on postoperative day 126. Donor-dominant one-way matching at HLA class 1 can be a high-risk factor for acute GVHD despite HLA class 2 mismatching.