This article presents the results of a validation process of the French version of the “Attention Deficit Hyperactivity Disorder - Orientation Scale” (ADHDOS), a tool used to establish the pattern of teachers’ beliefs about attention deficit hyperactivity disorder (ADHD). Analyses show that although some of the eight categories of beliefs of the ADHDOS have acceptable validity and reliability scores, the eight distinct entities that Bilton (1996) had proposed were not supported. Some suggestions are made concerning using the actual version of ADHDOS as well as for building a new version of the scale.