Introduction - In France, the suicide rate in 2011 was significantly higher in prisons than in the general population. We reviewed the evolution of the crude suicide rate in prisons since 1945 and sought to understand the trends observed. Materials and Methods - The suicide rate in prisons in metropolitan France since 1945 was compared to that observed in the general male population (aged 15 to 59). Data covering three and a half years of incarceration from the national inmate registry of the Directorate of Prison Administration (DAP) confirmed certain risk factors identified in the literature. Annual DAP data were used to describe changes in the incarcerated population that may have played a role in suicide trends. Results - From 1945 to 2010, the prison suicide rate rose significantly, from 4 to 19 per 10,000 people, and differed from the rate observed in the general population. Starting in 1955, the proportion of women became marginal, and the size of the prison population increased. After initially rising, the proportion of pretrial detainees declined. More recently, the use of short-term sentences has increased. The proportion of individuals convicted of sexual assault has risen, as has, more recently, the proportion of those convicted of intentional violence. Discussion-Conclusion - Prison conditions and the social and health profiles of inmates could not be studied over time, but changes in the criminal profiles of inmates likely played an important role in the rise in suicide. (R.A.)