Autism is a complex neurodevelopmental disorder characterized by impaired reciprocal social interaction, impaired communication, and restricted, repetitive, or stereotyped behaviors. Autism seems to affect more children than was previously believed, although this phenomenon may be due to broadening of the diagnostic criteria and increased awareness of the condition. Recent research has clearly indicated the importance of early identification, since early intensive treatment is associated with better long-term outcome. There are many controversies and competing theories about the etiology and treatment of autism, often leaving families confused about the best course of treatment and intervention. Pediatric primary health care clinicians have an important role in both the early identification and ongoing management of children with autism. It is, therefore, essential that primary care clinicians have up-to-date information about the science of autism.