Itraconazole is a triazole-derivative antifungal agent with an extremely broad spectrum of action in vitro, in experimental animals in vivo and in clinical trials. When taken orally, itraconazole achieves high and sustained levels of active drug in many tissues, including skin, nail and most deep organs. Its clinical value has been proved in all forms of mycosis affecting the skin and mucous membranes and in onychomycosis. In systemic infections, clinical trials have led to recommendations that itraconazole is the current drug of choice for blastomycosis, histoplasmosis, paracoccidioidomycosis, lymphocutaneous sporotrichosis, chronic disseminated aspergillosis and many cases of phaeohyphomycosis. It is also finding application in deep-seated Candida infections and in cryptococcosis. Its safety profile is extremely good, with very few non-trivial adverse experiences noted in a large series of patients treated and monitored. Itraconazole therefore represents a useful therapeutic advance for the management of most forms of fungal infection.