Single-agent homoharringtonine (HH) was evaluated as induction therapy in 20 patients with advanced acute nonlymphocytic leukemia (ANLL) in a pilot study of the Eastern Cooperative Oncology Group (ECOG). HH was given by continuous intravenous (i.v.) infusion at 3.5 mg/m2 on the first day and at 6.0 mg/m2/day on days 2-8. Fourteen men and six women with a median age of 43 years were treated. Sixteen patients had clearing of peripheral blasts, 10 patients achieved marrow hypoplasia, and 2 patients had progressive disease. No complete remission occurred. Drug-induced hypotension was the most significant toxicity, causing a delay in treatment in 8 patients. The median survival was 15 weeks (range 1-65 weeks) from the start of HH treatment. Despite a definite antileukemic effect, HH as a single agent cannot be recommended as a useful salvage regimen in patients with far advanced ANLL.