At our institution the selection of unrelated donors for hematopoietic stem cell transplantation (HSCT) relies on low resolution human leukocyte antigen (HLA)-A,B and high resolution HLA-DRB1,DQB1 DNA-based typing. To answer the question of whether routine high resolution HLA-A,B,C typing might improve HSCT outcome, 171 white "HLA-identical" donor/recipient pairs, as stated by our pretransplant tissue typing routine, were retyped for HLA-A,B,C using sequence based typing (SBT). The numbers of HLA-A,B,C allele mismatches detected by SBT were correlated to established clinical endpoints of HSCT outcome. We found 33.9% of the study transplants to be fully HLA-A,B,C matched, whereas 66.1 % exhibited one through four donor/recipient HLA-A,B,C allele mismatches. However, statistical analysis could not demonstrate an impact of the number of HLA-A,B,C allele mismatches on overall survival and other analyzed endpoints. Thus, our series of white donor/recipient pairs does not suggest the routine use of HLA-A,B,C SBT to improve HSCT outcome substantially.