There is a lack of research findings to guide the clinician who is faced with assessment and, especially, treatment of sex offending behavior in persons with intellectual disabilities (ID). However, the research that does exist suggests that one promising framework through which to guide treatment is through cognitive behavioral therapy (CBT) which is based upon individual case formulation. Whether the initial treatment is delivered in a residential or ambulatory environment, generalization of new skills to the community environment appears to be an inevitable and necessary part of treatment. CBT appears to be an effective strategy in reducing reoffending and improving behavioral skills for sex offenders living in the community. Sex offending behavior in persons with intellectual disabilities is a serious problem with significant and long-term consequences for the victims, offenders, and their communities. A growing awareness of such problems in persons with ID requires effective solutions with regard to assessment and treatment. This paper provides relevant background concerning the prevalence, characteristics, and vulnerabilities of intellectually disabled sex offenders, as well as guidelines for assessment and treatment. The paper describes Project STOP which provides assessment and treatment to adults with ID who have been convicted or identified as being at risk for sex offending behavior. An evaluation of the project revealed a low rate of recidivism and a high degree of treatment adherence. References