This work deals with the geographical study of a phenomenon that links man to his health: "The management of HIV/AIDS/tuberculosis co-infection at the CTA of the Brazzaville University Hospital". The aim of our research is to analyze the geographical and sociodemographic determinants of patients co-infected with HIV/AIDS and tuberculosis in Brazzaville, through a retrospective study. Analysis of the database enabled us to identify the social, demographic and geographical variables of co-infected patients. Spatialization of the phenomenon enabled us to identify the arrondissements with the highest rates of co-infected people in Brazzaville. The data analyzed are those from the passive database supplied by the CHU's CTA, providing fairly relevant information. The results show that TB/HIV co-infection in Brazzaville is ongoing, and that its extent within the population evolves according to the means of control and management. Its geographical spread depends on the degree of urbanization and demographic growth.