Between 1978 and 1988 (median follow up 5 1/2 years), 396 newly diagnosed adults with AML (age range 14-59 years, median 44) received STT comprising daily Adriamycin: 25mg/m2 for 3 days, Cytosine arabinoside (ara-C): 100mg/m2 bd and 6-thioguanine: 100mg/m2 bd, each for 7 days. A maximum of 6 cycles was administered with as short an intercycle time as possible. No further treatment was given. Complete remission (CR) was achieved in 243/396 patients (62%), 71 patients (18%) having resistant leukaemia and 82 (21%) dying within 6 weeks. Antecedent myelodysplasia and advanced age correlated unfavourably with achievement of CR (p = less than 0.001 and 0.005 respectively). Sixty nine patients continue in first remission between 2 1/2 and 12 years; the median duration of remission was 1 year. M3 morphology (p = 0.005) and absence of hepatosplenomegaly (p = 0.001) correlated favourably with duration of remission. Ninety one patients remain alive with an actuarial survival of 22% at 5 years. More recently, additional consolidation comprising high-dose ara-C and total body irradiation (TBI) with autologous bone marrow transplantation (ABMT) has been evaluated in an open study. CR has been achieved in 41/66 patients under the age of 50 but only 19/41 have proceeded to ara-C + TBI + ABMT. Twenty two have not (early recurrence 10, allogeneic BMT 4, debility 6, refusal 2). 11/19 who proceeded to ablative therapy continue in remission (4 treatment related deaths, 4 recurrences) as compared to 9/22 who did not. Currently the overall median duration of remission for the 41 patients intended to proceed is identical to that of age-matched historical controls illustrating the difficulties inherent in demonstrating benefit for the use of myeloablative therapy and ABMT in patients with AML in first remission.