Background: The purpose of this study was to describe what is known about HIV infection and other sexually transmitted diseases, infection transmission routes, care, and sources of information, from the viewpoint of men having sex with men. Methods: National data (n = 2,072) was collected from June to August 2010 in Finland as part of a joint internetbased survey conducted in 38 countries (EMIS, European MSM Internet Sex Survey). Results: The respondents' age, place of residence, highest education and employment status were statistically significantly related to how often the respondent sought information on HIV, testing and treatments, and what they knew about infection transmission routes. The respondents' information seeking behavior was not seen as active regarding HIV infection and other sexually transmitted diseases. Conclusions: We should also consider the possibility of using internet-based interventions, especially in smaller and northern catchment areas, in order to improve the knowledge level of men having sex with men.