The incidence of systemic fungal infections has risen sharply in the last two decades, reflecting a rise in the number of patients who are predisposed to these diseases because they are immunosuppressed or immunocompromised. The growing use of intensive chemotherapy to treat cancer, highly immunosuppressive drug regimens (not only in transplant recipients), widespread prophylactic or empirical broad-spectrum antibiotics, prolonged parenteral nutrition, long-term indwelling lines, improved survival in neonatal and other intensive care units, together with the AIDS epidemic have led to an upsurge in the number of patients at risk. In addition, there have been changes in the epidemiology of systemic fungal infections, with Aspergillus spp. and Candida spp. other than Candida albicans becoming increasingly common causes. These changes have affected the selection of drugs for first-line or prophylactic use, as not all agents have the critical spectrum of activity required. The management of systemic fungal infections can be divided into four main strategies: prophylaxis, early empirical use, pre-emptive and definite therapy. Antifungal prophylaxis is given based on the patient risk factors, but in the absence of infection. Empirical antifungal therapy is given in patients at risk with signs of infection of unclear aetiology (usually persistent fever) but of possible fungal origin. Therapy is given pre-emptively in patients at risk with additional evidence for the presence of an infective agent in a way predisposing for infection (e.g. Aspergillus colonization; high Candida colonization index). Finally, definite treatment is used in patients with confirmed fungal infection. The distinction between risk-adapted prophylaxis, early empirical therapy, and pre-emptive use of antifungals often becomes unclear and clinical decision making depends largely on local epidemiology and resistance patterns, adequate definition of patient risk categories, early diagnosis and the calculation of cost-benefit ratios. This article addresses the use of itraconazole in the treatment of invasive fungal infections in the haematology patient.