OECD countries have developed various practices and policy approaches to promote inclusive education systems for students with special education needs (SEN), which include learning disabilities, physical impairments and mental disorders. Among the latter, Attention-Deficit/Hyperactivity Disorder (ADHD) is a particularly relevant: being often comorbid with other learning disabilities, it causes significant difficulties in academic and social outcomes to affected students. Compared to other disorders that can cause difficulties to students, ADHD is less consistently accepted as an impairing condition. Mapping and analysing the key elements of diverse practices across OECD countries is fundamental to correctly define the situation of students with ADHD in education systems and the future direction of policy-making. Through a holistic approach, the paper adopts the analytical framework developed by the "OECD's Strength through Diversity project: Education for Inclusive Societies" to analyse policies and practices to include students with ADHD in education systems and promote their well-being.