The initiative began in February 2000, when CSC sought to offer drug abusing inmates separate units for more intensive drug interdiction and treatment services. These specialized units focus limiting the availability of drugs, and often provide a multi-faceted approach to drug treatment. Their main purpose is to offer a drug-free environment with enhanced support from staff. Inmates volunteer to reside in such units and agree to submit to additional drug testing and searches to minimize the availability of drugs. The article describes the five pilot sites in Canada and then presents data on a preliminary assessment of the pilot program effectiveness. Questionnaires were completed by 274 inmates and 72 staff members of the ISU's. Descriptive statistics about inmates who chose to reside in the ISU's are provided and show that, by and large, they resemble the male offenders in the inmate general population. Approximately 56 percent of the ISU inmates were serving a sentence for a violent offense and 64 percent had no prior Federal criminal history. Overall, the ISU's were considered a good idea by participating inmates and staff members and succeeded in providing a positive, drug-free environment. Future evaluations should focus on operational impacts specifically focusing of whether the units provide a safer environment. Tables, notes