From November, '85 to March, '87, 17 patients (12 males and 5 females, median 28 years) with resistant or relapsed ANLL received HiDAC (3 g/m2 c.i. 3 hs every 12 hs, day 1-4) + m-AMSA (100 mg/m2 i.v. day 5-7) as salvage therapy: 8/17 patients (47.1%) achieved CR, 7/17 (41.1%) were resistant and 2/17 (11.8%) died during induction; 8/10 relapsed patients achieved a 2nd CR, while all 7 primary resistant patients failed to. Median period of PMN less than 0.5 x 10(9)/l was 28 days, median period of PLTS less than 30 x 10(9)/l was 25 days. All patients had infections during aplasia. Median CR duration was 6.6 months, while median survival of responders was 10.6 months. Two patients with severe induction-related complications relapsed after 2 and 5 months, respectively: 1 patient underwent BMT and relapsed after 21 months; 5 patients, 4 of whom had received a prior ABMT during 1st CR, underwent ABMT: 3 died from ABMT related toxicity and 2 relapsed after 8 and 18 months, respectively. We conclude that HiDAC + m-AMSA is highly effective in relapsed, but not in resistant patients with acceptable hematologic and extra-hematologic toxicity. The role and modalities of ABMT in prolonging a 2nd CR are at present controversial.