The substantial increase in the prevalence of autism necessitates that practicing physicians become more familiar with the presentation of symptoms to improve early diagnoses and interventions, thus improving the prognosis for affected children. Autism is a complex neurodevelopmental disorder with a triad of core impairments in social interactions, repetitive behaviors, and communication. Clinically, autism appears as a spectrum, with many variations in the severity of defining behaviors and associated symptoms among children. Although the etiology of autism is unknown, it is thought to involve a genetic susceptibility that may be triggered by environmental factors. Because of the high variability in behaviors, biologic findings, and response to treatment, many specialists are assuming a theory of many different autisms, each of which may have a somewhat different etiology and response to treatment. Although there is no known cure for autism, many treatments are available to improve core and associated symptoms.