Limited qualitative research has examined teachers' understanding of Attention Deficit/Hyperactivity Disorder (ADHD), their attitudes towards the inclusion of children with ADHD in mainstream schools and how they support such learners. To address this, the current study used qualitative methodology to examine teachers' understanding of ADHD, their attitudes towards inclusion and their inclusive behaviours for children with ADHD. Semi-structured interviews were conducted with teachers (n = 10) working in 10 Scottish schools. A thematic analysis identified four themes: "ADHD Existence and Importance; Girls Go Under the Radar; The Impact of Limited Training; Working Inclusively." Teachers' perceptions may impact upon ADHD diagnosis and successful inclusion. The findings suggest the need for training to educate teachers about the causes of ADHD and the role of gender in symptoms. Classroom teachers should have access to more support to help them work successfully with children with ADHD. The study provides recommendations for teacher education and professional development surrounding ADHD.