Purpose - The purpose of this paper is to examine the challenges that arise when introducing an electronic identification (eID) card for professional use in a health-care setting. Design/methodology/approach - This is a case study of an eID implementation project in healthcare. Data were collected through interviews with key actors in a project team and with eID end users. The authors viewed the eID card as a boundary object intersecting social worlds. For this analysis, the authors combined this with an electronic government initiative challenge framework. Findings - The findings of this paper illustrate the interpretative flexibility of eID cards and how eID cards as boundary objects intersect social worlds. The main challenges of implementing and using eID cards in healthcare are usability, user behaviour and privacy. However, the way in which these challenges are interpreted varies between different social worlds. Practical implications - One of the implications for future practice is to increase our understanding of the eID card as a socio-technical artefact, where the social and technical is intertwined, at the same time as the eID card affects the social as well as the technical. By using a socio-technical perspective, it is possible to minimise the potential problems related to the implementation and use of eID. Originality/value - Previous research has highlighted the need for more empirical research on identity management. The authors contextualise and analyse the implementation and use of eID cards within healthcare. By viewing the eID card as a boundary object, the authors have unveiled its interpretative flexibility and how it is translated across different social worlds.