Background - The Winter Olympics in Turin, Italy, held from February to March 2006, featured certain sporting events taking place near Briançon, in the Hautes-Alpes. A public health surveillance system was established by the Hautes-Alpes Departmental Directorate of Health and Social Affairs and the Southern Interregional Epidemiology Unit, in order to rapidly detect any occurrence that might warrant preventive or public health control measures and to guide interventions in the event of an epidemic or environmental pollution. Method - Surveillance was conducted from January 30 to March 15, 2006, in the Briançon district, whose population (25,000 residents) triples during this period due to tourism. Mortality was monitored through deaths recorded by the Briançon civil registry and analysis of death certificates in the study area. A network of nine physicians, monitoring cases of gastroenteritis, influenza, and measles, was established. Two laboratories in Briançon provided information on the tests performed. Activities in the emergency departments of the Briançon Hospital Center and the Hautes-Alpes SAMU were monitored. The systems for reporting notifiable diseases and carbon monoxide (CO) poisoning were strengthened by raising awareness among reporting officials. Upstream, preventive measures were organized in Briançon and the surrounding area: food safety compliance, increased self-monitoring, improved water treatment, awareness campaigns on the risks of Legionella and CO, and inspections to ensure ski equipment met safety standards. Data were collected daily or weekly depending on the partner, but any unusual health event had to be reported immediately. The data, analyzed daily, were transmitted to health authorities every evening. A bilingual weekly feedback report was sent every Friday to the partners, the Italian health authorities, and the European Centre for Disease Prevention and Control. Results—Partner participation rates approached 100%, and deadlines for submitting information were met. No health events were identified in the monitored area. Mortality data, as well as emergency department activity (average of 58 visits per day) and emergency medical service (EMS) activity (average of 94 calls per day), were comparable to those from the same period the previous year. For their part, the Italian health authorities did not report any specific events. Discussion - This surveillance system proved to be appropriate and complementary to inspection and control activities. Its very high level of acceptance likely stems from the partners’ understanding of the system, which is structured around the ongoing, non-specific surveillance framework established with hospitals, the emergency medical service (Samu), and civil registries, supplemented by ad hoc systems (physicians, laboratories). Alerting the relevant stakeholders laid the groundwork for the collaboration that is essential in the event of an epidemic or environmental pollution. (R.A.)