The imprisonment is able to accelerate the declaration of some psychiatric problems until this latent or balanced.

The prison psychosis can be observed among new prisoners, and is charged to the conditions of imprisonment, and the difficulties of adaptations of the prisoner with his new medium.

The concept of prison psychosis is a much discussed concept whose limits with the other psychoses are very vague and thus posing a problem of diagnosis and pathogenesis, however one on simulation remains possible in front of the obviousness of the secondary benefit.

In this work, we will try to discuss, through a clinical observation, the nosographic place of this clinical entity.