Repositories play a crucial role in promoting and implementing the concepts of open science, which is recognized as the foundation of scientific work and research. In response to the challenges of open science and legal obligations, Croatian national institutions (among them the National and University Library in Zagreb) established a joint national infrastructure of digital repositories in 2015 – a place for the storage, long-term preservation, and open access to the scientific output of institutions within the science and higher education system. After nearly a decade of Croatian experience, it is necessary to answer the question – what is the role of repositories today, and are they truly accepted as a means to enhance the openness, reputation and visibility of institutions? The poster will present the national infrastructure of repositories within the Dabar system – Digital Academic Archives and Repositories, providing an overview of the system's development over the years. Currently, Dabar comprises 172 repositories and over 249 thousand objects, but only slightly more than 50% of the items are in open access. To determine the reasons for the high number of closed items, a questionnaire will be conducted among institutions that primarily store items in restricted or closed access. This research can be examined as a case study for further research on European and global levels. The results can contribute to a better understanding and identification of factors negatively affecting the implementation of open science practices and services, serving as a foundation for more systematic support where needed.