This paper investigates the usability of the core functionalities of an Institutional Repository on mobile devices. An EPrints-based repository (Covenant University Repository) was used as case study. The core functionalities of the Institutional Repository were modelled using the Unified Modelling Language and tested on five different mobile devices. Questionnaires were designed and administered to users of the repository based on known usability attributes and the results were analysed using SPSS software. Reliability and convergent validity of the questionnaire was estimated by Cronbach’s alpha and produced a result of 0.771, which is above 0.7 - the minimum recommended. Also, the results from the analysis of the usability attributes show that for all the attributes considered, each scored well above 4.00 on a scale of (1-5) which represents good usability. In essence, the results show that the current web version of the repository provides good usability when accessed from a range of mobile devices. The novelty of this work is that it presents a case study of mobile access to Institutional Repositories in an elegant and repeatable way
