Paracoccidioidomycosis is a subacute or chronic systemic mycosis caused by Paracoccidioides brasiliensis, a soil saprophyte and thermally dimorphic fungus. The disease occurs mainly in rural workers in Latin America and is the most frequent endemic systemic mycosis in many countries of South America, where almost 10 million people are believed to be infected. Paracoccidioidomycosis should be regarded as a disease of travelers outside the endemic area. The primary pulmonary infection is subclinical in most cases, and individuals may remain infected throughout life without ever developing clinical signs. A small proportion of patients present with clinical disease. The lungs are frequently involved, and the pulmonary clinical manifestations must be differentiated from many other infectious and noninfectious conditions. Diagnosis should be based on epidemiological, clinical, and microbiological data. Effective treatment regimens are available to control the fungal infection, but most patients develop fibrotic sequelae that may severely hamper respiratory and adrenal function and the patient's well-being.