Several recent studies have demonstrated a genetical overlap between autism and schizophrenia. However, at a behavioral level it remains unclear which features can validly distinguish adults with autism from an adult schizophrenia group. To this end, the present study compared 21 individuals with the autistic disorder and 21 individuals with schizophrenia in self-reported features of autism and schizophrenia, as measured by the Autism-Spectrum Quotient (AQ) and the Schizotypal Personality Questionnaire (SPQ). The schizophrenia group was more likely to report positive symptoms and the adults with autism were more likely to report impairments in social skill. Overlap was found between the two groups in negative symptoms, disorganization, attention to detail and imagination. Thus, when discriminating between the two disorders, especially social skill and the presence of positive symptoms are relevant, whereas the presence of negative symptoms is not indicative. (Contains 2 figures and 5 tables.)