Autism is an extremely complex neurodevelopmental disorder that is expressed in a spectrum of phenotypes and is characterised by impaired reciprocal social communication and stereotyped patterns of interests and activities. Its aetiopathogenesis remains poorly understood. This exhaustive synthesis discusses various aspects: A focus on the neurobiology of autism: the candidate genes implicate an involvement of numerous brain regions and a concomitant malfunctioning of neurotransmitter, immunologic, and other mechanisms; The most incisive rehabilitation models in their original formulation and the results achieved with the same or similar protocols in Italian centres (understanding, language therapy, social skill training; The psychopharmacologic options for the condition of autism per se and for its associated, very frequent, comorbidities. It suggests a potential influence on professional practice and enables an up-to-date approach to effective diagnosis and treatment.