Autism spectrum disorders are particularly difficult to diagnose in the presence of early profound deafness because of communication related issues. Two parts of the Autism Screening Instrument were administered to 13 deaf individuals with autism and two comparison groups: hearing autistic and deaf learning disabled. A parental questionnaire was also used. No differences in autistic symptomatology were found between the deaf autistic and the hearing autistic group. However, the deaf autistic group was diagnosed later than the hearing autistic group. It is concluded that autism can be diagnosed in the deaf; that it resembles autism in the hearing; and that it is not a consequence of deafness per se. Learning disabled deaf individuals who are not autistic do not resemble people with autism in behavioural terms. The findings have implications for remediation, education, and the emergence and management of challenging behaviours.