Norway has been a stronghold of restrictive attitudes and scepticism towards the use of methadone in treatment of heroin addiction. A policy of nation-wide use of methadone has now been adopted. This paper gives a short history of the use of methadone, a review of present neurobiological knowledge and a description of the different approaches in methadone based treatment. Methadone treatment does not reduce opioid dependency but compensates for neurobiological complications of long-term use. This increases the ability to profit from psychosocial approaches in treatment and reduces the tendency to risk-taking and socially disturbing behaviour. Norway aims to follow the "Swedish" model in methadone policy with emphasis on high threshold, high dose treatment combined with control and systematic rehabilitative measures. This choice should be evaluated both in a comparative and in a treatment oriented perspective.