In this review, we aim to compare different early treatment strategies of invasive fungal diseases in patients undergoing induction chemotherapy for acute myelogenous leukemia or myelodysplastic syndrome. Three treatment approaches--prophylactic, empiric, and preemptive treatment--are subject to continuous discussion among physicians treating patients at risk. Considering the available clinical basis of evidence, we opt for antifungal prophylaxis with posaconazole 200 mg tid po as our primary prophylactic strategy, while the employment of preemptive treatment should be delayed until more accurate diagnostic tools become available. In addition to antifungal prophylaxis, empiric treatment with caspofungin or L-AmB may be administered to patients with fever resistant to broad-spectrum antibiotic treatment and without radiographic findings typical of invasive fungal disease.