PurposeGhanaian public universities have fully embraced the concept of open access. This is evident in the increasing numbers of institutional repositories (IRs) by universities in Ghana. However, to ensure the sustainability of these IRs, it is vital the current IR infrastructure is capable of responding to current and future demands. The purpose of this study is to investigate the sustainability of the current IR infrastructure of public universities in Ghana.Design/methodology/approachThe convergent parallel mixed methods design was adopted. A total of 830 respondents comprising IR managers, library staff (digitisation and e-resources units), postgraduate students, lecturers and university librarians from five public universities in Ghana were sampled for this study. A questionnaire and a semi-structured interview guide were the main instruments used for data collection.FindingsThe findings of this study revealed that the IR infrastructure of public universities in Ghana is robust and has the capacity to expand when the need arises. However, funding, cost of internet connectivity, personnel and erratic power supply were identified as major challenges confronting IRs in Ghana.Originality/valueThis study highlighted Ghana's existing IR infrastructure situation. This study is a significant contribution to the literature from West Africa because there is not much research on IR infrastructure from this part of the world.