Background: Earlier studies point to the prevalence of attention deficit hyperactivity disorder (ADHD) to be similar around the world. There is, however, a wide variety in estimates. The prevalence of ADHD in youth has never been examined in France. Method: Starting with 18 million telephone numbers, 7,912 numbers are randomly selected. Among the 4,186 eligible families, 1,012 (24.2%) are successfully recruited. A telephone interview is administered to all families about a child in the 6 to 12 age range. It covered family living situation, school performance, symptoms of ADHD, conduct disorder (CD), and oppositional-defiant disorder (ODD), and other features of ADHD. Results: The prevalence of ADHD in France is between 3.5% and 5.6%. The population prevalence of treatment for ADHD is 3.5%. ADHD youth are more likely to be men than women, and, compared to non-ADHD children, ADHD children are more likely to have CD and ODD. Having ADHD is associated with a family history of the disorder. The ADHD youth are more likely to have had learning difficulties, to have repeated a grade, and to be functioning academically below grade level. Conclusions: The epidemiology of ADHD in French children is similar to the epidemiology of ADHD in other countries. The disorder occurs in between 3.5% to 5.6% of youth and is more common among boys than among girls. The authors replicate the well-known association of ADHD with CD, ODD, and indices of school failure. The impact of ADHD symptoms on school performance highlights the importance of screening for such symptoms in schools. (Contains 2 figures and 2 tables.)