This diploma paper deals with sentences of imprisonment in Croatian Criminal Law and its alternatives. The introduction outlines the definition of deprivation of liberties with special regard to imprisonment, long-term and short-term imprisonment and the historical overview of imprisonments. The second part of this thesis discusses the execution of imprisonment sentences, the classification and the rights of the prisoners and prison staff. Penalties are considered and defined as the oldest way of punishment. During the 19th and 20th century three fundamental theories about the purpose of sanctions, which are absolute, relative and mixed theories, have been formed. The purpose of sanctions has been elaborated in accordance to the theories mentioned above. Ultimately, sanction alternatives, work for the common good, suspended sentence, protective measures and the probation system of the Republic of Croatia are defined. In order to elaborate the above-mentioned data, sources like books, articles, legislation and the world wide web were used. It was concluded that during 2016, compared to the previous years, the number of prison sentences declined. Simultaneously, a growth of suspended sentences has been noted. The rise of recidivists and crime demonstrate the necessity to change the inadequate punitive policy. By applying suspended sentences continually, the purpose of sanctions, special and general prevention cannot be met. As a consequence, suspended sentences and the work for the common good should be applied more restrictively. Long criminal proceedings, recidivism, penal populism and excessive costs of the proceedings still constitute an issue, which solution is to find alternatives to prison sentences, especially probations.