This study examined benefits of methadone maintenance among prerelease prison inmates. Incarcerated males with preincarceration heroin dependence (n = 197) were randomly assigned to (a) group educational counseling (counseling only); (b) counseling, with opportunity to begin methadone maintenance on release (counseling + transfer); or (c) counseling and methadone maintenance in prison, with opportunity to continue methadone maintenance on release (counseling + methadone). At 90-day follow-up, counseling + methadone participants were significantly more likely than counseling-only and counseling + transfer participants to attend drug treatment (p = .0001) and less likely to be reincarcerated (p = .019). Counseling + methadone and counseling + transfer participants were significantly less likely (all ps < .05) to report heroin use, cocaine use, and criminal involvement than counseling-only participants. Follow-up is needed to determine whether these findings hold over a longer period.