Results indicated that the five actuarial risk assessment measures did not produce consistent rankings of sex offender recidivism risk. The average sexual offender had percentile rankings that varied by nearly 50 percentile ranks. Some offenders had rankings that varied between the lowest rank on one measure to almost the highest rank on another measure. A full 55 percent of the sample was identified by at least 1 instrument as being high risk while only a small proportion of the sample (3 percent and 4 percent, respectively) were identified as either high or low risk by all 5 instruments. Other findings indicated that the percentile rankings obtained in this study using the five instruments were similar to those reported by the instruments’ developers. The authors support the use of multiple actuarial measures and suggest that responsible risk assessors should combine the percentile ranks obtained by multiple measures into a mean or average percentile ranking. The research sample included 476 adult male sexual offenders who were assessed and treated at a medium-security penitentiary in Ontario, Canada. Researchers coded information from the offender’s files using the five actuarial assessment measures. Data were obtained from archived clinical files, the Offender Management System national database, and the Canadian Police Information Centre records. Files contained interview records, institutional reports, psychological test reports, and pre- and post-treatment results from group therapies. Statistical data analyses were conducted using the Statistical Package for the Social Sciences (SPSS) and Microsoft Excel spreadsheets. Future research should focus on the development of falsifiable theories of recidivism risk. Tables, footnotes, references