Paracoccidioidomycosis (PCM) is a chronic granulomatous infectious disease, whose etiologic agent is the fungus Paracoccidioides brasiliensis. The central nervous system (CNS) involvement with paracoccidioidomycosis (NPCM) occurs more frequently than has been admitted in the past. There are some major histocompatibility complex antigen association studies with systemic paracoccidioidomycosis. Some indicate a positve association with HLA antigens, but there is no study with the involvement of the CNS. To investigate why not all cases of systemic PCM show the involvement of the CNS and whether genetic factors are involved, we studied 6 patients with NPCM, from the neuroinfection outpatient clinic. The patients were typed for class I and class II antigens by a microlymphocytoxity standard test. The HLA antigen frequencies found in this study in patients with NPCM were not different from the alleles frequencies observed in the Paraná population.