Project HARAPAN was a 2×2 randomized, controlled trial of a prison-based, pre-release methadone program and an evidence-based behavioral intervention (HHRP) for HIV-infected, opioid dependent prisoners in Malaysia. Participants were randomized to one of four study arms: methadone only; HHRP only; methadone and HHRP; control/standard of care. Participants were interviewed at baseline, day of release from prison, and then monthly for 12 months post-release. Primary outcomes included retention in HIV care, retention in substance dependence treatment, time to relapse to drugs, and time to re-incarceration.