One hundred and sixteen adult patients aged 14-73 with previously untreated acute myeloid leukaemia received induction and consolidation chemotherapy with daunorubicin, cytosine arabinoside and thioguanine. Two novel approaches to post consolidation therapy have been investigated. Patients aged 50 years or less who had no suitable matched allogeneic donor were considered for autologous bone marrow transplantation (BMT) using bone marrow which had been cultured in vitro for 14 d. Patients over the age of 50 years with normal bone marrow cellularity and peripheral blood count were treated with a single oral dose of busulphan 100 mg/m2 (without BMT rescue) 3 months following the completion of consolidation therapy. Eighty-seven patients (75%) achieved a complete remission. Of 70 patients who completed consolidation therapy, 40 were aged less than or equal to 50 years and 30 were greater than 50 years. Forty-three patients went on to receive post consolidation therapy in first CR (autologous BMT 12, allogeneic BMT 7, busulphan therapy 24). The event-free survival at 4 years was 47% for autologous BMT, 34% for allogeneic BMT and 45% for busulphan-treated patients. The survival for the older cohort of patients who received post consolidation therapy with single dose busulphan therapy was encouraging, and this agent should be considered for future post consolidation strategies.