These facts led to the present multicenter, phase II, single arm, open study, performed by the Northern Italy Leukemia Group. There will be approximately 12 participating centers, which will enroll a total of 100 patients. Patients will receive caspofungin, starting from the first day of induction chemotherapy for leukemia, as a single daily dose intravenously at the dosage of 70 mg q.d. and followed by 50 mg q.d. thereafter until documentation of complete hematologic remission after the first induction cycle or of leukemia persistence after one cycle of induction and one cycle of salvage chemotherapy.