The purpose of this dissertation is to verify which prison policies towards users of narcotic drugs, psychotropic substances or substitutes best respond to problems related to the presence of drugs in the penitentiary system and to provide their justification in the theories of punishment. In this thesis, I use models of drug policies available in the community and I try to adopt them to prison settings. In this way, I propose theoretical models of the prison policies towards users of narcotic drugs, psychotropic substances or substitutes. I argue that the therapeutic model of prison drug policy, assisted with elements of other models, is the most suitable reaction to holistically viewed problems connected to the presence of drugs in the penitentiary system. Next, I analyze the reaction of the Polish penitentiary system towards drug users. Furthermore, I try to justify the purpose of the therapeutic model in the theories of punishment. Theories of punishment are traditionally developed within either a utilitarian framework (where punishment is used to deter future wrongdoing and maximize the happiness of society) or a retributive framework (where punishment helps to restore the balance of society upset by criminal behavior). Utilitarian theories of punishment are criticized for their philosophical justification for the violation of individual rights, and retributive theories exclude or marginalize rehabilitation. In this thesis, I demonstrate an alternative ethical justification of punishment towards incarcerated drug users reaching to Aristotle's virtue ethics. The purpose of punishment in aretaic theotries is not utility or justice, but rather human flourishing. Finally, I critique the therapeutic model of prison policies towards people who are users of narcotic drugs, psychotropic substances or substitutes from the point of view of other models.