In endemic areas, the systemic mycosis paracoccidioidomycosis (PCM) is the most frequent etiology of Addison's disease. Paracoccidioides brasiliensis, the causative agent of PCM, exhibits a high tropism for the adrenal glands, which results in a low hormone reserve and in more severe cases, in symptoms of primary adrenal insufficiency. In these cases, the hormone deficit is usually treated with replacement corticoid therapy for the rest of the patient's life. Recently, we identified three patients with disseminated PCM who had adrenal insufficiency; one of them had Addison's disease. All showed complete recovery of adrenal function after a 1–2-year period of specific therapy with ketoconazole or sulfonamides. Plasma cortisol levels were determined by radioimmunoassay of baseline blood samples, as well as those taken after the rapid stimulation test with synthetic adrenocorticotrophic hormone, and before and after the antifungal therapy.