Suicide is one of the leading causes of death in prisons worldwide. In France, the suicide rate among prisoners is 18.5 suicides per 10,000 inmates—seven times higher than in the general population. Among the risk factors identified in the literature, those most strongly associated with suicide in prison are physical isolation in custody, a history of mental illness, and a history of suicide attempts. Suicide prevention in prison involves several measures, including treatment of mental health disorders, improvement of living conditions in custody, social support for prisoners, and the use of specific tools and programs by prison staff. No program for the prevention of recurrent suicidal behavior has ever been implemented. We propose adapting “VigilanS,” a program already used in the general population, for the prison population.