French Guiana, like the rest of the Amazon region, has long been considered a low-risk area for Chagas disease, with forest-dwelling vectors and a wild animal reservoir. Changes in the epidemiology of this parasitic disease in the Amazon, against a backdrop of ecological upheavals, and warning signs from preliminary studies in French Guiana prompted an epidemiological and entomological assessment mission by the French Institute for Public Health Surveillance (InVS) in March 2005, in cooperation with the French Research Institute for Development (IRD). This assessment confirms the presence of Chagas disease in French Guiana, with indigenous transmission that is not limited to forested areas. Nine of the 15 human cases diagnosed between January 1990 and March 2005 are linked to infection in French Guiana’s riverine regions. The circulation of Trypanosoma cruzi (T. cruzi) has also been demonstrated along the coast, including in the residential area of Cayenne and adjacent municipalities. Indeed, reduves are readily found in the immediate vicinity of homes, with a high rate of T. cruzi infestation. Vector intrusions into homes and gardens are frequent, particularly near residual forest patches, and are responsible for cases of Chagas disease in domestic dogs. This review covered all available data, which are far from exhaustive. Thus, the incidence and prevalence of Chagas disease are unknown. The few serological studies conducted do not allow for an estimate of the prevalence of T. cruzi infection; consequently, the transfusion risk cannot be assessed. The risk of an endemic situation emerging in the inhabited and urban areas of French Guiana is real and justifies the establishment of a surveillance system for Chagas disease. (R.A.)