Numerous studies of autistic individuals have revealed evidence of cerebral hypoperfusion, neuroinflammation, gastrointestinal inflammation, immune dysregulation, oxidative stress, relative mitochondrial dysfunction, and neurotransmitter abnormalities. Many of these findings have been correlated with core autistic symptoms. For example, cerebral hypoperfusion in autistic children has been correlated with repetitive, self-stimulatory and stereotypical behaviors, and impairments in communication. Specifically, hyperbaric oxygen therapy (HBOT) has been used and can compensate for decreased blood flow by increasing the oxygen content of plasma and body tissues. The aim of this work was to study the effect of hyperbaric oxygen therapy in autistic Egyptian children. HBOT is a treatment that has recently become quite popular in the autism spectrum disorder (ASD) community. Its benefits cross a wide range of autistic traits as: improved language, increased awareness, behavior and socialization by affecting the pathophysiological findings in autism.