Introduction - Regular mortality surveillance conducted by the French Institute for Public Health Surveillance (InVS) revealed an increase in mortality in France during the winter of 2008–2009. The purpose of this article is to describe fluctuations in mortality during the winter of 2008–2009 compared to previous winters. Methods - Using death data reported by INSEE and population estimates from 2003 to 2009, mortality rates per 100,000 inhabitants for the winter of 2008/2009 were compared to rates from previous years. The analysis was conducted by age group and by region. Results - During January 2009, the mortality indicator adjusted for population change exceeded the values observed during the three previous winters. This result is particularly evident among the oldest individuals (aged 85 and over) and is distributed unevenly across regions. Between weeks 4 and 12 of 2005, mortality had already reached a similar level. Discussion-conclusion - This initial descriptive study does not provide a comprehensive assessment of the mortality episode observed in early 2009. The concurrent occurrence of several factors (cold snap, respiratory illness, and seasonal epidemics) during the same period may at least partially explain this phenomenon, although it is not currently possible to assess their respective roles in this increase. (R.A.)