The purpose of this study was to conduct a cost - effectiveness analysis of detoxification from heroin using buprenorphine in a specialist clinic versus a shared care setting. A randomized controlled trial was conducted with a total of 115 heroin-dependent patients receiving a 5-day treatment regime of buprenorphine. The specialist clinic was a community-based treatment agency in inner-city Sydney. Shared care involved treatment by a general practitioner supplemented by weekend dispensing and some concurrent counselling at the specialist clinic. Quanti. cation of resource use was limited to inputs for treatment provision. The primary outcome measure used in the economic analysis was the proportion of each group that completed detoxification and achieved an initial 7-day period of abstinence. Buprenorphine detoxification in the shared care setting was estimated to be $24 more expensive per patient than treatment at the clinic, which had an average treatment cost of $332 per patient. Twenty-three per cent of the shared care patients and 22% of the clinic patients reported no opiate use during the withdrawal period. These results suggest that the provision of buprenorphine treatment for heroin dependence in shared care and clinic appear to be equally cost - effective.