Dengue infection that is accompanied by unusual complications has been described in Brazil. We report on the presence of dengue virus in the central nervous system (CNS) of a patient who died in 1998 in Rio Grande do Norte, northeast Brazil. DEN-2 viruses were isolated from the brain liver, and lymphnode tissue of a 67-year-old man whose signs and symptoms were those of dengue infection and a secondary immune response. A postmortem revealed nose bleeds a liver that was brownish with yellow areas, and pulmonary and cerebrae congestion. Immunoperoxidase staining showed a dengue antigen-specific positive reaction in the gray matter cells of the cerebrall cortex; a granular citoplasmatic reaction was seen in the neurons. Dengue infection should always be considered as a cause encephalitis in tropical countries, especially in those where the disease is endemic.