In the master's thesis, the author analyses and compares the procedure of enforcement of the prison sentence in the Slovenian and English systems, both in terms of legal regulation, as well as the actual situation and conditions in prisons. In both legal systems, the area is predominantly under administrative jurisdiction; in Slovenia, the authority for the enforcement of criminal sanctions is the Administration of the Republic of Slovenia for the Enforcement of Criminal Sanctions, while in England and Wales it is Her Majesty's Prison and Probation Service. The master's thesis presents the procedure of reception to the prison, living conditions in prisons, food, clothing, release from prison etc. In both systems the goal of prison sentence is rehabilitation of prisoners, therefore treatments and activities are carried out for the prisoners from the beginning of the sentence, and they have the opportunity to work or to gain an education. The problems faced by both systems are the overcrowding of prisons and the high rate of persistent offenders. Prisoners have better conditions in the Slovenian system, as it gives them more rights and better standards. The system of visits is better organised, the prisoners have the opportunity to spend more time outdoors, higher hygiene standards, better food quality, out-of-prison benefits are included in the length of the sentence, and the living conditions are better defined. English prisons also carry out some very effective and interesting practices which the Slovenian system is not familiar with and should be considered to be transferred into the system, such as greater emphasis on psychological assistance to newly admitted prisoners, greater role of religious communities, the possibility to choose between several menus at meals, the possibility of communicating with prisoners by e-mail, cheaper calls from prisons, providing work to most prisoners and supervision of prisoners after release. Another difference between the two systems is also in the method of granting release on licence, namely in England certain prisoners are automatically released on parole after half of their sentence, while in Slovenia all applications for parole are examined by a parole board.