OBJECTIVE: To evaluate the efficacy of tacrolimus for prevention of graft-versus-host disease (GVHD) in patients receiving allogeneic bone marrow transplants. DATA SOURCES: Published literature was identified through MEDLINE (January 1990–December 1998) using the key words tacrolimus, FK506, graft-versus-host disease, and bone marrow transplant. DATA SYNTHESIS: GVHD associated with allogeneic bone marrow transplant is a serious life-threatening complication. An evaluation of studies using tacrolimus for prevention of GVHD was conducted. CONCLUSIONS: Tacrolimus is effective for the prevention of GVHD in allogeneic bone marrow transplant. Further studies need to be conducted to optimize the dosage schedule and to determine therapeutic ranges, efficacy, and safety.