Introduction. In 2005–2006, Réunion Island experienced the largest chikungunya outbreak ever recorded. A dedicated surveillance system was established to monitor the progression of this outbreak. Since then, the system has remained operational and has undergone several updates. Its objectives are to detect cases early and to monitor the epidemiological situation of the disease. Methods. During the inter-epidemic period, surveillance is based on comprehensive case finding. If the situation evolves into an epidemic, a shift to the sentinel physician network allows for the estimation of the weekly incidence of the disease. Surveillance of severe cases and deaths is also conducted. Results. In 2005–2006, the number of symptomatic chikungunya infections on Réunion Island was estimated at 266,000, representing an attack rate of 34%. A total of 222 severe cases and 44 cases of mother-to-newborn transmission were identified. Since the end of the epidemic, two indigenous clusters have occurred in the western part of the island, in 2009 and then in 2010. The second cluster was more intense in terms of duration and impact, with 164 cases, 112 of which were laboratory-confirmed. Conclusion. The experience gained in recent years, particularly during the major 2005–06 epidemic, has enabled Réunion to establish a sensitive and responsive chikungunya surveillance system that has already proven its effectiveness and responsiveness by detecting the emergence of two disease outbreaks at an early stage.