Background: This article aims to explain and elaborate upon the recently released ICD-11 criteria for Autism Spectrum Disorder (ASD, World Health Organization), which endorse a medical model. Method: We integrate insights from several disciplines (e.g., psychology, linguistics, sociology and lived experiences) to reflect the scientific and ethical insights derived from the biopsychosocial, neurodiversity perspective on autism. Results: First, we describe the core domains of ASD’s behavioural characteristics and then the lifetime, developmental perspective on the manifestations of these behaviours. Subsequently, we discuss potential underlying neuropsychology, related behaviours (i.e. associated features/conditions) and we consider some similarities and differences with the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM 5, American Psychological Association). Conclusions: Recommendations for clinical application are provided. For instance, diagnostic classification in clinical practise should be a means to provide proper, suitable care, and therefore all diagnostic assessments should be used to tailor interventions and/or care to the capacities and genuine needs of the people that ask for professional help.