One of the major health problems among HIV seropositive patients is superimposed infection due to the defect of immunity. Furthermore, intestinal parasite infection, for example, Isospora belli. The infection for this parasite is more frequent in tropical and sub-tropical climate areas. In the Brazil studies they were accomplished in Ribeirão Preto/SP´s city, Rio de Janeiro/RJ, Santos/SP e Campinas/SP, which presented high levels of isosporosis. In this study, 422 feces stool examination was performed and the patients were screened for a history of diarrhea, which was defined as loose stool occurring more than three times a day and interns in the Giselda Trigueiro hospital in the Natal city - Brazil, which revealed a distribution of 13.3% of the I. belli compared to the data of Africa countries (8 -20%), probably due to the humid climate and the satisfactory few resources found in these areas