Attention Deficit Disorder (ADHD) is gaining media attention and permeating the educational universe. In the midst of so much information, research shows that there are gaps when it comes to the teaching and learning process of children in the literacy phase. With this in mind, the purpose of this book is to provide reflections on ADHD in the classroom and its didactic-pedagogical implications. The theoretical and conceptual framework is based on Lev Vygotsky, whose contributions can be used to think about mediation in the school environment. The aim is to analyse the pedagogical practices of teachers in relation to the construction of knowledge for students with ADHD in the Early Years of Primary School. To do this, we sought to understand - based on current scientific literature - what obstacles ADHD causes to children in everyday school life and what possibilities Early Years teachers can use to mediate in the classroom. This is a qualitative approach. The study indicates the need to encourage significant changes not only in teaching practices but also in the entire technical, administrative and pedagogical school staff.