Antisocial personality disorder (APD) and the more severe personality disorder of psychopathy both have particular relevance to forensic populations, but it is only recently that these constructs have begun to be explored in forensic populations who have intellectual disabilities. This paper reviews the emerging theoretical and empirical evidence in this field. Consideration is given to conceptual issues, the validity of the constructs, and emerging evidence for reliability and validity of existing measures in this particular forensic group. The lack of treatment outcome studies with respect to APD and psychopathy in this group is noted. While these constructs may be useful in understanding and treating some offenders with intellectual disability, these such labels can also result in negative outcomes for individuals. Caution is indicated in their broad application until further relevant research is completed.