OUTLINE: This is an open label, randomized, multicenter study. Patients are stratified according to center, site of infection, underlying disease, and baseline neutrophil count. Patients are randomized to one of two treatment arms. Arm I: Patients receive voriconazole IV every 12 hours for 7-28 days and continue with oral voriconazole twice a day for a maximum total duration of 12 weeks of therapy. Arm II: Patients receive intravenous amphotericin B daily for at least 2 weeks; treatment continues for a maximum of 12 weeks. Patients discontinued from study drug treatment because of toxicity, intolerance or clinical failure may receive alternative (nonstudy) antifungal therapy. All patients are monitored for a total of 16 weeks.