Autism Spectrum Disorder is a very complex developmental disorder which begins in early childhood, it is often diagnosed in the first three years of life and lasts a lifetime. It is characterized by the fact that it affects almost all mental functions, there is damage to various developmental areas from social interaction and communication, and stereotypical forms of behavior occur. It is not completely clear how this happens. It is important to recognize these symptoms as early as possible and make a diagnosis so that the child can be included in rehabilitation and proper treatment in time. Therapy is adapted to the child's needs, and the most important thing is for the child to acquire social skills and become as independent as possible. This paper deals with the topic of Autism Spectrum Disorder and a case report of a nine year old boy L.L. that is divided into three parts. The first part discusses autism, historical development, the characteristics of the disorder, developmental disorders in the Autism Spectrum, such as pervasive developmental disorders (Atypical Autism and Disintegrative Disorder), Asperger Syndrome and Rett Syndrome, diagnosis, autism spectrum assessment tools, and early intervention. The second part is dedicated to the case of a nine year old boy L.L for whom I was a teaching assistant. Paying particular attention to data such as observed symptoms, social integration, patterns of behavior, intellectual abilities and cooperation of the professional team, educators, teachers, assistants and parents. The third part talks about educational integration, methods and procedures in teaching children from the Autism Spectrum. The importance of inclusion and acceptance of people with Autism and the importance of their inclusion in society is emphasized, throughout the paper. It is also important that educators and teachers become as familiar as possible with this disorder in order to successfully and properly involve children in Autism Spectrum in education.