Fungal infections have become an important problem in intensive care units (ICU) as a consequence of the relative insensitivity of available diagnostic methods, the delay in instituting therapy, the high cost and the poor prognosis associated with high mortality. Empirical treatment has been recommended for ICU patients who have identifiable predisposing factors for developing fungal infections and high suspicion without positive cultures for fungal species. The administration of empirical antifungal therapy is associated with some principal questions: which is the right time to initiate treatment, which drug, at what dose and for how long. The responsiveness, the toxicity and the daily cost of treatment are parameters to be taken into account in order to choose chemotherapy as precise guidelines are still not available. In this review the empirical therapy of fungal infections in ICU and the proposed therapeutic strategies to overcome problems arising in everyday practice are discussed. Pneumon 2005, 18(1):34-45.