Open government data (OGD) has emerged as a crucial aspect of dig- ital transformation strategies, prompting many governments to establish national OGD portals to facilitate access to large amounts of public sector datasets. How- ever, despite the OGD portals’ goal of serving as intermediaries between OGD producers and OGD users, they have faced numerous criticisms for their low use and failure to adequately meet users’ needs. The lack of consensus within the OGD community on the sources of dissatisfaction with the OGD portals and their negative impact on their use warrants a detailed examination of users’ dissatisfy- ing experiences. Taking a user-centred perspective, I adopt a critical incident technique (CIT) approach to identify the drivers and sources of dissatisfaction with a national OGD portal. Based on my analysis, a descriptive model is pro- posed to help to comprehend the interrelations between three sources of dissatis- faction with the OGD portal and ten respective drivers: OGD production (i.e., development of high-quality datasets, completeness of the metadata), OGD dis- tribution (i.e., accessibility of the datasets, organisation of the datasets, centrali- sation of the datasets, search engine, interface, visualisation), and OGD use (i.e., skills and knowledge, and added value).