We treated 16 patients with myelodysplastic syndromes with 24 courses of bolus topotecan. Patients received topotecan as a daily 15 minute infusion for 5 days at 3 dose levels (4.0 mg/m2/d, 2.0 mg/m2/d or 2.5 mg/m2/d). There was one complete response and one partial response (overall response rate 12%). Toxicity included myelosuppression, diarrhea, ileus and mucositis. There were 3 treatment-related deaths. The results of this schedule of topotecan appeared to be inferior to that reported with infusional topotecan in patients with MDS.