The current clinical trial is designed to provide posaconazole (SCH 56592) to subjects with invasive fungal infections a)which are refractory or resistant to standard antifungal therapies or b) for which there are currently no effective therapies. Subjects with such invasive fungal infections cannot be enrolled in controlled, randomized clinical trials. Secondly, this clinical trial is also designed to provide posaconazole (SCH 56592) to subjects with invasive fungal infections who c) have experienced serious or severe toxicities while receiving standard antifungal therapies or d) have pre-existing organ dysfunction such as renal dysfunction who require standard antifungal therapy which is precluded because of the toxicities associated with such therapy. This clinical trial also serves to allow collection of preliminary data regarding the safety and efficacy of posaconazole (SCH 56592) against a variety of invasive fungal infections which although serious and life-threatening are sufficiently rare so that they cannot be studied in a controlled, randomized clinical trial.