Purpose This paper aims to carry out a literature review on the implementation of digital preservation policies, strategies and actions by institutional repositories. The objective is to identify, out of the published experiences, at which level they are fulfilling the function of ensuring the long-term availability of the deposited materials. Design/methodology/approach Using a systematic literature review methodology, a total of 21 articles from international refereed journals published between 2009 and 2020 are reviewed. Findings The research production on this subject is very limited. The scarce number of published articles proves that the interest of repository managers has been focused on issues other than to assure the long-term availability of the assets they store. The literature review has not found clear evidence about how institutional repositories are implementing digital preservation. It is particularly striking the lack of works focused on the situation in European countries. More field studies are needed. They would allow to extract conclusions and produce best practices to help managers to improve preservation strategies. Originality/value This study has shown that one of the main functions of repositories is not being dealt with as promised by repository managers. More work in this area is needed. In particular, it is necessary for a study at the European level to gather detailed data that will allow to draw a portrait of the current situation, extract conclusions and produce best practices to help managers to improve or develop preservation strategies.