Sollicitudo rei socialis (Latin: The Social Concern) is an encyclical letter promulgated by Pope John Paul II on 30 December 1987, on the twentieth anniversary of Populorum progressio.

And since it is a doctrine aimed at guiding people's behavior, it consequently gives rise to a "commitment to justice", according to each individual's role, vocation and circumstances.

(Para.41) The condemnation of evils and injustices is also part of that ministry of evangelization in the social field which is an aspect of the Church's prophetic role.

41)The pope continues in this letter his development of the term "structures of sin",[1] used in his earlier apostolic exhortation, Reconciliatio et paenitentia (1984).

"Structures of sin" are defined in the Catechism of the Catholic Church as "social situations or institutions that are contrary to the divine law".