Autism spectrum disorders (ASD) include several clinically different disorders. Despite the impression that in recent years there has been a rise in the incidence of this disorder, it seems that the apparent rise stems from the widening of diagnostic criteria rather than from a true rise in disorder incidence. Notwithstanding the wide range of clinical symptoms, reliabLe information on the etiology of this disorder is lacking. However, new data points to an important genetic component and to structural changes in the brain. There is a wide range of comorbidities with additional neurodevelopmental disorders. The currently offered treatment is multi-disciplinary and includes primarily behavioral therapy and symptomatic treatment with psychotropic drugs.