The author criticizes the concept of whole life sentence from the aspect of the European standards of protection of the rights of persons deprived of their liberty. The aim of the paper is to contribute scientific critique of new solutions on life imprisonment in Serbian Criminal legislations, because the life imprisonment was introduced in 2019, but the conditions on serving the sentence are not prescribed. Conditional release of convict for certain serious crimes are forbidden. On the contrary, the relevant acts of the Council of Europe and the decisions of the European Court of Human Rights (ECHR) show that the principle of social reintegration of offenders must be ensured in the national enforcement system, otherwise there is a risk of violating Art. 3 of the European Convention. The state has an obligation to include lifelong prisoners in prison rehabilitation programs, as well as establish and use mechanism to reduce sentences. Using examples from Italy and the Netherlands, the author examines the circumstances due to which the standards of ECHR of execution of life imprisonment in those countries have not been reached. In that way, the attention of the legislator in Serbia is drawn to the fact that the principle of effective offender's rehabilitation (also his right of rehabilitation) must not be neglected even when the crime needs to be reacted to the strongest sanctions, with a lifelong imprisonment.