Oxidative stress is now believed to play a crucial role for neurodevelopment disorders such as autism spectrum disorders (ASD) and attention deficit hyperactivity disorder (ADHD). To review the most recent literature regarding the role of oxidative stress for the pathophysiology of ASD and ADHD, we conducted a systematic search of the relevant literature and further discuss the clinical and research implications of this knowledge. A systematic search in PubMed database retrieved 132 articles, of which 33 were included in the review. This review found relevant evidence concerning the role of oxidative status in ASD and ADHD, albeit with some contradictory findings. In order to overcome the incongruities found, more studies are needed in the study of neurodevelopmental disorders, with more thorough study designs and particular attention to the accuracy of the diagnostic tools used for the cases included.