HBOT has been shown to increase oxygen delivery to hypoperfused or hypoxic tissues, decrease inflammation and oxidative stress. The mechanism of clinical improvements in ATEC, CARS, and SRS scores in the children studied may be secondary to increased oxygenation of underperfused areas of the autistic brain, reduced neuroinflammation, decreased oxidative stress, or a combination of these. This case series suggests that low pressure HBOT improves symptoms in autistic children. Further research in this area, including HBOT trials in autistic patients, using observers blinded to the intervention, is now needed to test this hypothesis.