The objectives of the second edition of the Coquelicot survey were to describe the profiles and behaviors of people who use drugs (PWUD), to estimate the prevalence of HIV and HCV, and to evaluate harm reduction policies. The survey was conducted in 2011 using a random sample of IDUs recruited from specialized facilities in five urban areas and two French departments. The eligibility criteria for participating in the survey were: having injected or snorted drugs at least once in one’s lifetime, being of legal age, and being French-speaking. A biological sample was collected from IDUs who completed the questionnaire. Preliminary results show a 75% participation rate. With a total of 1,568 respondents, the sample consists mainly of men. A large proportion of them are in precarious social situations. The average age is 39 years. HIV and HCV seroprevalence rates are 10% and 44%, respectively, and vary by age and city. HCV seroprevalence has been declining since the first edition of the survey in 2004, particularly among those under 30. HIV seroprevalence remains stable. Since injection practices remain common among younger individuals (56% of IDUs under 30 have injected at some point in their lives, including 53% in the past month), harm reduction efforts must continue. (R.A.)