Abstract: From May 1983 to November 1984,5 patients with acute leukemia,2 adults and 3 children, were treated with fetal liver transplantation prepared by intensive chemothrapy and TBI.4 of them showed evidence of engraftment and 1 had I GVHD suggested by clinical signs and skin biopsy.3 patients recovered completely and are alive for 21,16 and 12 months respectively.One patient,transplanted after the remission of his third relapse,remitted for 115 days and died of relapse on the 133th day after FLT.The other one gained marrow reconstraction and complete remission on the 38th day after transplantation,but died of interestitial pneumonia on the 64th day.