A prevalence survey of serum markers for hepatitis B (HBV) and C (HCV) infections was conducted from 2003 to 2004 using a national sample of individuals covered by the general health insurance scheme. This survey was part of the performance agreement established between the French Institute for Public Health Surveillance and the Ministry of Health for the period 2002–2004. It was also part of the national program to combat hepatitis C (1999–2002) and subsequently the national hepatitis C and B plan (2002–2005), which included strengthening surveillance of hepatitis C and B among its priority areas. This report, following a review of the objectives and methodology, summarizes the initial results of the study and places them in context with previous estimates and in relation to the objectives of the national program and plan, in order to adapt strategies for combating hepatitis C and B.