Hundreds of fungal species have been associated with pulmonary diseases in humans, but few are consistently found to cause pneumonia. This paper reviews the clinical presentations, geographic prevalence, and epidemiology of, as well as the most recent, yet readily available, diagnostic methods and general therapy for the more common fungal pneumonias. The chapter is divided into categories based on the fungi's physiological and growth characteristics, clinical presentations, and prevalence in the environment. Sections include the geographically restricted dimorphic fungi (e.g., Blastomyces, Coccidioides, Histoplasma, Paracoccidioides, Sporotrichum, and Penicillium mameffei), the more globally found yeasts (e.g., Cryptococcus neoformans and Candida), other hyaline moulds (e.g., Aspergillus, Zygomyces, Fusarium, and Trichosporon), as well as the dematiaceous fungi (e.g., Altemaria, Bipolaris, Curvularia, Pseudallescheria, and Xylohypha). Pneumocystis carinii is also discussed since it is now accepted as being more closely related to the fungi based on analysis of its 16S-like RNA sequences.