Patients online access to their EHR together with the rapid proliferation of medical information on the Internet has changed the way patients use the information to learn about their health. It is well documented that patients often turn to the Internet to find information about their health and care. However, little is known about patients information seeking behaviour when using online EHRs. By using information horizons as an analytical tool this paper aims to investigate the information behaviour of cancer patients who have chosen to view their EHRs (readers) and to those who have not made that option (non-readers). Thirty interviews were conducted with patients. Based on information horizons, it seems that non-reading is associated with living in a narrower information world in comparison to readers. The findings do not suggest that the smallness would be a result of an active avoidance of information, or that it would be counterproductive for the patients.