Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by persistent challenges in social communication and interaction, alongside restricted and repetitive behaviors. The prevalence of ASD varies by region, has been rising, and is more common in males. Current management of ASD requires a comprehensive approach involving a combination of therapies (behavioral, speech, occupational) and medication. Despite significant efforts, effective treatment of ASD remains challenging. Recently, cell therapy has emerged as a promising potential treatment for neurological conditions, including ASD. This chapter provides an overview of preclinical studies of cell therapy for ASDCell therapyfor autism spectrum disorder, administering umbilical cord mesenchymal stem cellsMesenchymal stem cells (MSCsMesenchymal stem cells), human adipose-derived stem cells, mesenchymal stem cells, and human amniotic epithelial cells. This chapter also discusses the application of cell therapy in humans, highlighting existing inconsistencies in cell sources, processing methods, dosages, and delivery routes. Furthermore, our phase 1 and 2 studies suggest that combining autologous bone marrow mononuclear cellsMononuclear cellsfrom bone marrow with educational intervention was safe and resulted in better outcomesOutcomes compared to educational intervention alone. However, given the controversy surrounding cell therapy for ASDCell therapyfor autism spectrum disorder, further randomized studies are needed to confirm its efficacy.