Book excerpt: The relationship between autism and PTSD has historically been neglected in research and understanding but impacts the lives of many. Autistic people are intrinsically vulnerable to traumatic social situations and relationships, which can later manifest as PTSD. Navigating situations where one feels entirely at odds can lead seemingly commonplace events to be processed as traumatic experiences. In this unique collaboration, Lisa Morgan and Mary Donahue explore PTSD in autistic adults as patient and practitioner. Lisa shares her personal experiences as an autistic adult, reflecting on emotionally traumatic events and their effect on her daily life. Mary examines the challenges surrounding diagnosis, reworking and developing communication and clarifying the symptoms of PTSD within the autistic population. Combining lived experience with professional expertise, this clear and accessible guide will provide a better understanding of autism and PTSD, providing support and direction to autistic adults processing trauma and those involved in their care.