Autistic disorders are pervasive developmental disorders, which are characterised by social, communicative and stereotyped, repetitive behaviour patterns. The onset of these disorders is in early childhood and they are most likely of biological origin. A review of neuropsychological questions and results is presented. Special features are found with regard to intelligence, attention, memory, speech, executive functions, theory of mind and central coherence. The different neuropsychological features are explained in terms of an integrated model which takes into account the elementary functions, systems of functioning and the underlying theoretical concepts. Autistic disorders can be understood as an integration deficit of these different functions.