In today’s society, all citizens who need digital information to manage their everyday life must be able to access it and trust it. They should have enough knowledge to use information and communication technologies (ICTs) and online health information (OHI) in an intended and purposeful way. The broader aim of this paper is to present and discuss health knowledge management (KM) from senior users of the online health information point of view. The theoretical point of departure is based on an understanding of health, knowledge and the Internet as social practices. This paper investigates e-Health literacy (eHL) and KM in health amongst seniors aged 65-90. It presents a case study on how they access, apprais, share and apply OHI in comparison to the way they use face-to-face health-encounters. Data comes from 17 open-ended interviews. E-HL and KM concepts are used to analyse and describe online behaviour and knowledge management in health as an interplay between individual and social factors. The results show how participants engage in self- and co-management of their own or others' health and illustrate how they get or receive help to understand OHI. By examining how they use ICT and do (not) trust OHI regarding “serious cases,” this paper provides critical insight into ways seniors acquire information and how they appraise, understand or trust in it. Their information-seeking activities are performed mainly in private settings, seldom with professionals. They have lower levels of trust in their own, individual appraisal skills, compared to collective searches and discussions. Norwegian seniors are cool and pragmatic, and emphatic on the “when needs must, see your GP!”. By examining differences in ICT use, knowledge acquisition and support given or received, the results pinpoint how providers must affirm seniors’ ICT use and individual and collective online health behaviour as assets for healthy ageing. A potential barrier for citizens’ use of OHI and health technology is the built-in understanding of health as an individual capacity and ICT use as an individual activity, compared to a contemporary understanding of health and the Internet as social practices and collective resources. Designers of health technologies and OHI should critically consider built-in understandings of content and users to enhance accessibility and value for citizens of all ages.