Background: The triad of impairments characteristic of autistic spectrum disorders and severe challenging behaviours are reasonably common among adults with intellectual disabilities. The aim was to investigate whether they had an impact on lifestyle among such adults living in staff-supported community housing. Methods: Data were collected on the adaptive and challenging behaviour, social impairment, attention from staff, social and community activities, household participation and engagement in activity of 427 adults living in 146 staffed houses. Presence of the triad of impairments characteristic of autistic spectrum disorders was based on items from the Disability Assessment Schedule. Categorization of severe challenging behaviour was based on scores on two domains of the Aberrant Behavior Checklist. Participants were divided into groups with and without the relevant characteristics and sub-samples selected which were matched on Adaptive Behavior Scale scores. Lifestyle outcomes were compared. In addition, multiple regression was used to examine the association between lifestyle outcomes and the presence of autistic spectrum disorders or severe challenging behaviours after controlling for other participant characteristics. Results: After controlling for adaptive behaviour, there were no significant differences between those with and without the triad of impairments. People with severe challenging behaviour received significantly more staff attention but were similar in terms of social, community and household activities. The regression analyses found small negative associations between Aberrant Behavior Checklist scores and variety of social and community activities and household participation after controlling for Adaptive Behavior Scale scores. Conclusions: Results support previous findings that low adaptive behaviour has a negative impact on lifestyle outcome. Compared with this, the presence of autistic spectrum disorders or severe challenging behaviour has little effect.