Some of the major future healthcare challenges are related to demography, finances and the technological development. In search for solutions the field of ‘E-health’ is often discussed. Lately, in these discussions there has been a focus on the importance of creating patient-centrered applications. Associated with the democratisation of the healthcare service and the development of “the informed patient” an important part involves the accomplishment of increased personalized medical information online. By exploring E-patients’ heterogeneity, this paper aims to support the development of patient-centered E-health applications. Using a qualitative approach, the paper reports from 25 in-depth interviews performed with Swedish patients and representatives of patient associations. By means of theoretical ideas from information science, four important components of Epatients’ information use environment (People, Problem, Setting, and Problem resolution) serve as instruments to illustrate and exemplify E-patients’ heterogeneity. The results draw a complex and dynamic picture of the E-patient context introducing a dimension of personalization reaching further than patients’ general online activities and individual medical data. This dimension of personalization is discussed in relation to tentative implications for the development of patient-centered E-health applications.