The exact assessment process will depend on a number of factors such as the characteristics of the offender, the purposes of the assessment, and the information potentially available to the assessor. In determining an individual's overall treatment needs, static actuarial assessments should be combined with functional analysis and assessment of stable-dynamic factors. Considering stable dynamic factors provides an indication of the individual's criminogenic needs areas that should be addressed in treatment. Examining dynamic factors can also assist in determining whether the risk level has changed. In addition to the assessment of risk, responsivity factors should also be considered as these will play a role in how effective any particular treatment program will be for an individual. These different assessment procedures can be sensibly combined so that the results of earlier processes can guide decisions about the use of additional procedures. In the field of sexual offender rehabilitation, this chapter describes up-to-date thinking around the assessment of sexual offenders in terms of what needs to be addressed in treatment. Notes and references