The declared aims of custodial sentencing worldwide and in Lithuania are to protect society from crime and reduce recidivism; it is agreed that these aims can be achieved only when the duration of imprisonment is devoted to the prisoner’s gradual return to society (UNODC 2015). However, the newest Lithuanian strategic documents note that the sentencing system does not promote the change of prisoners’ criminal habits, offender resocialization is fragmented, and prison staff carries out offender protection and surveillance, not resocialization and social help (LR Vyriausybė 2021b). By building upon the ideas of social constructionism tradition (Berger and Luckmann 1999) and critical criminology (Christie 1999; Hulsman 1997; Quinney 2004; Mathiesen 2006), this paper analyzes the aims of custodial sentencing in the context of Lithuanian penal system’s reform and specifies possible implementational problems of declared aims of imprisonment. Document analysis showed that the raising and naming of imprisonment problems are conditioned by the commitment to international organizations and projects, as well as the cascading aims of the Lithuanian political agenda. In Lithuania, the purposes of custodial sentencing continue to be relatively general and instrumental. They are used to justify current and future means of reform while it is expected of correctional facilities to provide long-term positive influences on a person and fulfill quantitative indicators. We presume that resocialization and social integration ideas, as the main declared aim of custodial sentencing, are “imprisoned” in political discourse, which lacks critical analysis and does not provide much chance for success.