Despite the increased prevalence of psychiatric disorder amongst offenders with an intellectual disability (ID), there is very little known about the characteristics and needs of those with dual disability. A study of admissions to a new community forensic dual disability clinic during the first 10 months of its operation. Typically, the offenders are male, are older than other offenders, exhibit long-standing and continuing serious behavioural disturbance (independent of their psychiatric diagnosis or level of involvement with the criminal justice system) and require supported or custodial accommodation, despite only mild or borderline levels of ID. Although only one-third have a diagnosable major nonparaphilic psychiatric disorder, three-quarters have had prior or current contact with psychiatric services and two-thirds suffer chronic medical illness. These offenders suffer psychosocial disadvantages far more extensive than those implied by the psychiatric or disability label. The multiple services provided to this group have been ad hoc, poorly co-ordinated and sometimes dangerously inappropriate. A service provision model is required which must be integrative and consistent. We suggest the use of multiskilled key workers, who maintain close contact with individual clients. Their role will be to implement management plans from the various specialist agencies who become involved with this group and provide long-term follow-up of their recommendations.