The polygraph, also referred to as the lie detector, records change in four physiological parameters associated with the autonomic nervous system. Care must be taken when interpreting polygraph findings with training and experience required if it is to be used appropriately. This article discusses the use of the polygraph in the treatment and supervision of sex offenders, and how techniques, such as the polygraph which may be perceived as repressive, can be used to benefit patients. Polygraphy can contribute substantially to treatment programs and assist offenders to avoid the sorts of behaviors that increase their risk of reoffending. Thirty-two men from 3 probation areas and taking part in sex-offender treatment programs participated in a study which examined whether the introduction of polygraph examinations would assist offenders in avoiding behaviors that might contribute to the risk of reoffending. The results of this study suggest that the most effective use of the polygraph may be a “truth facilitator” rather than a lie detector. It can bring worrying behaviors to the attention of supervisors and treatment providers, allowing effective intervention and additional treatment before offending occurs. References