Introduction. A pilot study was done to test the feasibility and effectiveness of buprenorphine as maintenance treatment for opioid dependent prisoners in Tihar prisons, India. This was the first such intervention in a South Asian prison. Methods. The study had a pre-post test design with quantitative, qualitative and biochemical assessments at baseline and at three, six, nine and twelve months after initiation of treatment with buprenorphine. Psychosocial intervention was provided in both, group and individual sessions. A total of 133 opioid dependent inmates fulfilling the eligibility criteria of the study were recruited in the study from November, 2008–March, 2012. Results. The study sample mostly comprised pretrial remand prisoners (95.3%) and most(94.3%) were repeat offenders. For most patients(95.3%), heroin was the primary drug of abuse. 50.3% were currently Injecting Drug Users (IDUs). Among the IDUs, sharing of syringe/needle was reported by 70% and paraphernalia by 49% in their drug using careers. Treatment was initiated with buprenorphine and the mean dose (in mg) of buprenorphine was 4.3± 2.0, 4.6± 1.9, 4.3 ±1.4, 4.3 ±1.5 given on 3,6,9&12 months respectively. Retention in the prison arm was excellent (98%) and compliance among those retained in prison was 100%. In the prison, during the course of the study, 10, 3, 1 prisoners reported injecting drug use at 3, 6, 9 months respectively. No reporting of injecting drug use was obtained at 12 months and thereafter. No other illicit drug use was reported at follow up. This was corroborated by results of urine screening suggestive of minimal or no drug use at follow up during imprisonment. A statistically significant reduction was found in severity of dependence, craving for drugs and withdrawal symptoms at follow up. Recognition of co-morbid health problems and appropriate treatment of the same was provided to the prisoners on OST. In qualitative assessments, most prisoners expressed satisfaction with treatment and reported experiencing OST treatment as their first ray of hope in their lives. Conclusion. Buprenorphine maintenance for opioid dependent prisoners was found to be feasible and effective in Tihar prisons. An upscale of this intervention in prisons in the region both as a drug treatment and harm reduction strategy is advisable. Funded and Supported by. United Nations Office of Drugs and crime(UNODC- ROSA) under Project RAS H/71 Implemented in. Tihar Prisons, Delhi, India Acnowledgement. Ms. Christina Albertin, Regional representative, UNODC- ROSA; Prof. Rajat Ray(retd): ex HOD Psychiatry and Chief NDDTC