Introduction - In April 2008, the Nice University Hospital (CHU) reported nine cases of measles, including one healthcare worker, to the Alpes-Maritimes Departmental Directorate of Health and Social Affairs. An investigation was launched to document the circulation of the virus and describe the clusters of cases identified in the Provence-Alpes-Côte d'Azur region and in Monaco. Methods - Case identification was conducted from March to May 2008 based on a survey of the first cases, notifications submitted to the DDASS, and a search for biologically confirmed cases through laboratories. Results - Thirty-six cases, including 5 healthcare workers, were identified, primarily in the Alpes-Maritimes. Half of the cases were aged 20 years or older. Two clusters of cases involving nosocomial transmission were identified. Following the alert, awareness-raising efforts regarding diagnosis, the implementation of preventive measures, and case reporting through mandatory reporting were carried out in hospital settings. The immune status of healthcare workers was verified through medical records, serobank data, or new specimens. Discussion - The debriefing meeting that followed this investigation once again highlighted the importance of raising healthcare workers’ awareness regarding the diagnosis and rapid reporting of measles cases, updating their vaccination status, and recommending vaccination for individuals born before 1980 who are not immune. Furthermore, isolation in a negative pressure room upon admission should be recommended for patients presenting with a febrile rash pending diagnostic evaluation. (R.A.)