Ten patients experiencing primary graft failure after allogeneic bone marrow transplantation received autologous marrow or blood cells as hematopoietic rescue 21-40 (median 22.5) days after the original transplant after which immunosuppression with cyclosporine was tapered off rapidly. The leukocyte count at the time of rescue was 0.1-0.3 x 10(9)/l with < 0.1 x 10(9)/l neutrophils. The clinical course was uneventful after rescue with hematologic recovery to 0.5 x 10(9)/l neutrophils occurring 9-61 days (median 20) later in nine patients, and to 50 x 10(9)/l platelets 17-595 days (median 40) later in eight patients. No patient had a life-threatening infection at the time of or after rescue. No patient experienced acute graft-versus-host disease. Four patients with acute leukemia had recurrent disease 46-117 days after autologous rescue, and died of relapse. Five patients with acute leukemia are alive in continuous remission at 270-3382 days, and one patient with chronic myeloid leukemia is alive in hematologic remission at 228 days. We conclude that infusion of back-up autologous cells can prevent the immediate infectious consequences of primary allogeneic graft failure through consistent myeloid recovery, and may result in long-term survival of patients with good-risk disease.