Ethnographic interviews and focus groups were conducted (05/2003-01/2004) among injecting drug users (IDUs; n=29) in Budapest, Hungary to assess HIV, Hepatitis B and C (HBV and HCV) related knowledge, norms, attitudes and behaviors. Participants perceived themselves at low risk for infection with HIV but high risk for hepatitis through injection but not sexual exposure. They reported strong disclosure norms for HIV and hepatitis infections, while sexual and injecting risk behaviors were influenced by trust about partners' self-report of infection status. Injecting networks were small, with infrequent syringe sharing among a few close friends. Cookers and drug filters were often shared, and filters were re-used as a backup drug supply. Most sexual relationships were monogamous, where condoms were rarely used. Although participant norms supported HIV/HBV/HCV testing, the lack of available testing facilities was a barrier to getting tested. Strong norms for infection disclosure and for getting tested coexist with engaging in risk behaviors with injecting and sex partners who are close friends. Network interventions among IDUs in Hungary should build on disclosure norms and trust to reduce injecting and sex risk. Testing services should be expanded and access increased so that IDUs can act on and reinforce their norms for testing.