Placebo responses are frequently observed in research and clinical contexts, yet there is limited knowledge about the placebo effect in among people with neurodevelopmental disorders. This presentation reviews the nature of the placebo effect in Autism Spectrum Disorders (ASD) and provides an outline of the mechanisms underlying placebo responding in ASD. In contrast to common belief, placebo responses are widely evident in studies investigating treatment effects among individuals with intellectual disability or ASD. Understanding the role of placebo effects in ASD may help discern genuine treatment effects from contextual factors in clinical trials. This has the potential to improve the development of more effective research methods and treatments for core ASD symptoms. Also, a better understanding of the psychosocial factors associated with placebo responses may improve the delivery of care for individuals with ASD.