Intellectually disabled clients pose serious problems both for the criminal justice system, and for corrective services. Case workers in the community are aware that many of their clients are committing criminal offences. Sometimes these offences are not brought to the attention of the police, because professionals are only too aware of the vagaries of the criminal justice system, and the possibility of prison for their client. On occasion, the offences are too numerous or too serious to be overlooked or dealt with informally. Once the client becomes involved with the criminal justice system, unfortunately prison is often the only alternative, because the judiciary feel that they have no alternative, owing to issues of public policy, or the protection of the community, or lack of secure units or other therapeutic programs in the community, but to consign the intellectually disabled defendant to prisons (Hayes & Hayes, 1984). A recent study of the prevalence of intellectual disability in the New South Wales prison population found 12-13 per cent of a sample of prisoners from five New South Wales gaols to be suffering from an intellectual disability, that is, significantly sub-average functioning which is characterized by inadequacy in adaptive functioning. The study found that approximately two percent of the prison population had an IQ of less than 70 and the remaining ten percent had IQs which placed them in the borderline range between 70 and 80, but their severe deficits in social and adaptive skills affected their level of disability and their ability to survive independently in the community. Female prisoners were doubly disadvantaged, and almost all of them had a dual diagnosis of intellectual disability and psychiatric, behavioural or emotional disorder. There were higher proportions of intellectual disability amongst the Aboriginal population, and Aboriginal inmates in comparison with the white prisoner population had marked deficits in communication skills. (It could be argued that more culture-fair assessments would reduce the numbers of Aborigines in the intellectually disabled group, but the counter argument to this is that if Aborigines are handicapped by their level of communication skills in written and verbal expression and receptive language areas, then they will be disadvantaged both in the criminal justice system, and in the prison system.) A number of the intellectually disabled prisoners had other disabilities and other physical health risk factors, most notably hearing impairment, and drug and alcohol addiction. The range of offences committed by the intellectually disabled prisoners indicates that this group is involved in serious crimes as well as nuisance crimes, although less likely to commit crimes requiring detailed advanced planning. The fact that intellectually disabled offenders have sometimes committed serious and violent offences has important implications for the availability of