From the immunological standpoint,1–5 liver allografts are more resistant to hyperacute rejection than are other solid organ grafts. Therefore, until recently, donor/recipient blood type (ABO type), human leukocyte antigen (HLA) matching, and crossmatch tests were not considered in clinical liver transplantation. In this report, we demonstrated that: (a) crossing the ABO barrier must be avoided except in extreme emergency; (b) HLA class I matching effect on liver allografts is as acceptable as in kidney transplantation, although, with regard to the effect of Class II matches, there are remarkable differences depending on the patients' original disease; and (c) anti-donor lymphocytotoxic antibodies (positive crossmatch) adversely affect liver allograft survival rates.