This paper describes the clinical-seroepidemiologic characteristics of patients with paracoccidioidomycosis (PCM) who visited the University Hospital at the State University of Campinas (Campinas, Sao Paulo, Brazil). The study group consisted of 584 individuals (492 males and 92 females) with ages ranging from 5 to 87 years. The highest incidence of the disease occurred between the ages of 41 and 50 years for men and between 11 and 40 years for women. Rural activities were the principal occupation of 46% of the patients. The diagnosis was confirmed by histopathologic examination and demonstration of fungus in scrapings, secretions, or in the sputum. Serologic test results for PCM were positive in 80% of the 584 patients studied. The significant number of patients, including 33 children less than 14 years old, indicates the presence of the fungus in the area and that this region is an important endemic area for PCM.