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.