Autism spectrum disorder (ASD) is a neurobiological developmental symptom complex characterized by early onset of deficits in verbal and nonverbal communication skills, socio-communicative function, and repetitive behaviors. The well-documented increased frequency of seizures and abnormal electroencephalographic (EEG) findings in ASD support the concept that the central nervous system dysfunction has a neurobiological basis. We review the prevalence of seizures and EEG abnormalities in children with ASD and explore the possible clinical significance of this correlation.