The article by Lehnhardt and colleagues successfully links empirically based facts with the authors' own clinical experiences from a specialized outpatient clinic for people with high-functioning autism; it can therefore be used as a practice guideline for the diagnostic evaluation of adults with suspicion of autism spectrum disorders (1). However, the population described in this paper accounts for only about half of people with autism spectrum disorders. According to Fombonne, 30–74% of individuals with autism spectrum disorders have below average intelligence (2). In both, individuals with and without additional intellectual disability (ID), autism spectrum disorders often remain undiagnosed until adulthood. In fact, autism spectrum disorders were diagnosed as such in only every fourth affected individual (3). This is not least owing to the fact that specific diagnostic instruments have yet to be developed (3, 4). According to the Conventions of the United Nations on the Rights of People with Disabilities and the Charter for people with autism adopted by the EU, all individuals with autism spectrum disorders have the right to receive diagnostic evaluation and appropriate treatment. We think that adequate availability of services for individuals with ID and suspicion of autism spectrum disorders would be a highly desirable goal in Germany.