The concept of electronic health (eHealth) literacy evolved from the social and information sciences and describes competencies necessary to use electronic health services. As it is a rather new topic, and as there is no current overview of the state of the art in research, it is not possible to identify research gaps. Therefore, the objective of this viewpoint article is to increase knowledge on the current state of the art of research in eHealth literacy and to identify gaps in scientific research which should be focused on by the research community in the future. The article provides a current viewpoint of the concept of eHealth literacy and related research. Gaps can be found in terms of a missing “gold standard” regarding both the definition and the measurement of eHealth literacy. Furthermore, there is a need for identifying the implications on eHealth developers, which evolve from the measurement of eHealth literacy in eHealth users. Finally, a stronger inclusion of health professionals, both in the evolving concept and in the measurement of eHealth literacy, is needed in the future.