Histoplasmosis is one of the most common opportunistic fungal infections in immunocompromised patients in endemic areas. We report the first two microbiologically documented cases of histoplasmosis in Taiwan. The first patient, with acquired immunodeficiency syndrome and a depleted CD4+ lymphocyte count, presented with a history of prolonged fever, papular skin rashes, pancytopenia and elevation of liver enzymes. He was diagnosed and treated initially for systemic toxoplasmosis, but the microbiologic and pathologic findings of the autopsied specimens disclosed disseminated infection caused by Histoplasma capsulatum. The second patient, an elderly man receiving corticosteroids for adrenal insufficiency, manifested with laryngeal histoplasmosis and was successfully treated with ketoconazole.