The objective of this study was to identify clinical subgroups in children with childhood autism and to examine comorbidity in each subgroup. The study was based on medical records of 30 inpatients referred to a specialist ward for children with pervasive developmental disorders. Eighteen consecutive patients with an IQ above 50 and fulfilling research criteria for childhood autism were grouped in accordance with the Wing's social subgroups of autism (aloof, passive, and active but odd). Comorbidity, in terms of deficits in attention, motor control, visuo-motor and visuo-spatial function, as well as epilepsy, was described in each of the three groups. The aloof and passive groups produced a pure autistic triad of deficits, while the active but odd group was characterized by strong comorbidity.