Psychiatric patients are significantly more often smokers than the general population, the only known exception being obsessive-compulsive disorder (OCD) and catatonic schizophrenia. We have investigated nicotine use in subjects with autism spectrum disorders (ASD). Ninety-five subjects (25 females and 70 males) consecutively diagnosed with any ASD and of normal intelligence were included in the study. Only 12.6% were smokers, compared with 19% in the general population and 47% in a control group of 161 outpatients diagnosed with schizophrenia or a schizophreniform disorder. The results suggest that smoking is rare among subjects with ASD, while the opposite was shown for schizophrenia. If replicated, this finding could suggest biological differences between non-catatonic schizophrenia and ASD, and support the theory of a biological link between ASD and a subtype of OCD, and between ASD and catatonic schizophrenia.