Two groups of patients with acute myeloid leukaemia (AML), treated concurrently, were compared to assess the support required during bone-marrow hypoplasia. One group of patients received drugs to induce initial remission; patients in the other group (in first remission) each received a bone-marrow transplant from a matched allogeneic sib. The patients who received marrow transplants required less time in hospital, were febrile on fewer days, received less therapeutic antibiotic treatment, and had fewer bacterial infections. They also required half as many units of platelets and blood per 100 days. The mean weight-loss per patient was the same in each group, and no patient required intravenous feeding. Transplantation for AML in first remission requires less supportive care than initial remission induction.