A patient had severe combined immunodeficiency syndrome and X-chromosomal recessive heredity. Since the parents and siblings were not suitable as HLA-compatible bone marrow donors, stem cells from embryonic liver were transplanted intravenously in 3 stages (6 X 10(6); 3.5 X 10(6), and 9 X 10(7]. Transplantation was tolerated well; there were no signs of a graft-versus-host reaction. Examination of the immunological condition after transplantation showed evidence of T-cell reconstitution, immunohistochemistry revealed beginning immune globulin production. The child died at the age of 5 months due to respiratory failure.