The aim of this study is to investigate the characteristics of the Internet users in Croatia related to seeking health information, which information they seek, the reasons, and the outcomes of that information on them. We surveyed the users of the Internet health portal 'Cybermed', in spring 2003 and autumn 2004. Responses were collected from a pop-up questionnaire, which appeared at every website visit. There were 369 respondents in 2003 and 580 respondents in 2004. Most respondents were women (82% in 2003 and 80% in 2004). While more than half of the respondents (55%) in 2003 had a college or university degree, this changed in 2004, when only 40% of respondents had a college or university degree (P < 0.001). Also, we recorded a significant age-related change, suggesting that the average age of the respondents increased in 2004 (P < 0.001). The leading motivation for seeking medical information was 'unanswered questions after visiting a physician'. Most respondents (90% in 2003, 87% in 2004) went online to seek information on a specific illness or condition. Women sought information for friends and colleagues more often than men (42% vs. 28%, P = 0.031) in 2003, while these differences were diluted in 2004. Approximately half of all respondents discussed the information they found online with their physicians. Patients who feel they were given insufficient information, or simply seek more information than the physician provided, turn to using online health information, which no longer seems to be reserved to those with the highest education degrees. Health-care providers should consider creating health-related Internet portals, supplementing the information they provide.