Objective: To describe hepatitis B and C knowledge and self-reported infection and risk behaviour in a group of Vietnamese men living in inner-urban Sydney, in order to assist with future program planning. Methods: Data were collected through telephone interviews conducted in Vietnamese using a structured questionnaire from 499 of 761 eligible men contacted, giving a response rate of 66%. The data were weighted to be consistent with the age distribution of Vietnamese men in the area. The findings were compared with a published national telephone study. Results: Low knowledge levels of hepatitis B and C were found when compared with data from a published national telephone study. The factors associated with higher mean knowledge scores for hepatitis B were being highly acculturated (P < 0.001), ever having been tested for HIV (P < 0.001) and knowing someone with HIV (P < 0.0001). For hepatitis C, the factors were being highly acculturated (P < 0.001), ever injecting drugs (P < 0.05) and being vaccinated for hepatitis B (P < 0.001). Knowledge regarding hepatitis B was particularly poor. High rates of self-reported hepatitis B infection were noted. Of the participants, 7.2% were aware that they had ever been infected with hepatitis B, more than 10 times the rate in the national telephone study. Conclusion: Lower levels of hepatitis B knowledge have been identified in a community with higher numbers of people living with chronic hepatitis B. Targeted community-wide awareness-raising campaigns and health care worker education is required to improve knowledge of hepatitis B and rates of screening in the Australian Vietnamese community.