Background: Irinotecan and temozolmide achieve objective responses in patients with Ewing sarcoma which recurrences after initial therapy. Optional dose schedules have not been defined. Procedure: We reviewed published series of patients treated with irinotecan and temozolomide for Ewing sarcoma which recurred after initial therapy. We compared objective response rates for patients who received 5 day irinotecan treatment schedules to response rates for patients who achieved 10 day irinotecan treatment schedules. Results: Among 94 patients treated with a 10 day irinotecan schedule there were 48 objective responses (51%). Among 218 patients treated with a 5 day irinotecan schedule there were 65 responses (30%). Conclusion: When we use irinotecan to treat Ewing sarcoma we should administer 10 days of treatment.