Advocates of shock incarceration programs have proposed that their strict military discipline and treatment programs provide an institutional environment that supports rehabilitation. Using the Prison Environment Inventory, this study compared a group of shock incarceration inmates' evaluations of the environment with those of a group of inmates housed at a minimum-security traditional prison. Shock incarceration appeared to be successful in providing external controls (e.g., safety, discipline) related to an environment that supports rehabilitation, but did not differ from the traditional prison in providing support related to internal change (e.g., emotional feedback). Future research should explore how shock incarceration, or other correctional settings, can provide the support and emotional feedback that promote psychological and emotional change. Notes, tables, references, appendixes