Patients with secondary acute myeloid leukaemia (AML) following treatment with alkylating agents and/or radiation show a poor response to standard induction therapy. Between 1983-1987 8 consecutive patients were treated with high-dose cytosine arabinoside (HD-ARA C; 3 g/sqm twice daily for 6 days) or intermediate-dose cytosine arabinoside (ID-ARA C; 0.5 g/sqm twice daily for 6 days). Complete remission was achieved in 3 patients (HD-ARA C: 2/3l; ID-ARA C: 1/5) and partial remission in 3 patients (ID-ARA C: 3/5). One patient (HD-ARA C) died during prolonged aplasia, one patient (ID-ARA C) proved refractory to treatment. The respective duration of remission in the 3 responsive patients was 3, 7 and 8 months. The probability of survival of the whole group was 50% after 12 months and 25% after 24 months. Our results confirm the efficacy of monotherapy with ARA C in the treatment of secondary AML. Consolidation therapy with ID-ARA C for 4 days seems to prolong remission.