Objective: To review the existing literature on transcranial photobiomodulation (tPBM) treatment effects on Autism Spectrum Disorder (ASD), in search for an effective treatment of a symptom cluster identified largely by contributions from late Dr. Biederman who asserted that they frequently present with Attention Deficit Hyperactivity Disorder (ADHD). Method: A survey of two databases, PubMed and PsycINFO, for clinical trials reporting on tPBM treatment in ASD was performed. Identified manuscripts that met eligibility criteria were then reviewed. Results: Three original manuscripts reporting findings on a heterogenous group of study methods met the eligibility criteria. Despite the heterogenous nature of study designs, findings from all three studies reported tPBM treatment to be associated with improvements in ASD symptoms. No serious or treatment limiting adverse events were reported. Conclusions: A nascent body of research suggests further clinical studies investigating efficacy of tPBM in treatment of ASD symptoms should be supported. "(J. of Att. Dis. 2024; 28(5) 664-668)"