Offenders with a history of opioid dependence are a particularly difficult group to treat. A large proportion of offenders typically relapse shortly after release from prison, commit drug-related crimes, and then are arrested and eventually re-incarcerated. Previous research demonstrated that oral naltrexone was effective in reducing opioid use and preventing recidivism among offenders under federal supervision. The 111 opioid-dependent offenders in this study were under various levels of supervision that included county and federal probation/parole, a treatment court, an alternative disposition program, and an intermediate punishment program. Subjects were randomly assigned to receive 6 months of either 300 mg per week of oral naltrexone plus standard psychosocial treatment as usual (n = 56) or standard psychosocial treatment as usual (TAU) without naltrexone (n = 55). While the TAU subjects who remained in treatment used more opioids than the naltrexone subjects who remained, the high dropout rate for both groups made it difficult to assess the effectiveness of naltrexone. The study provides limited support for the use of oral naltrexone for offenders who are not closely monitored by the criminal justice system.