This paper shows that preventing suicide risk in French prison regulations is thwarted in 2 prisons by professional criteria regarding credibility & solidarity, as well as by the balance of power between prisoners & guards, in addition to the realization, on the part of judges responsible for sentencing, of the risk posed by recidivists. The results of the study should provoke a re-evaluation of suicide prevention programmes when considered in the light of the numerous mediations & transcriptions between these programmes & their subsequent concretization in the culture & practices of prison employees. (33 refs.)