In view of the HIV epidemic and in order to increase the proportion of drug injectors engaged in a treatment programme, the Swiss national government decided in 1991 to stimulate new activities and projects in the field of drug abuse including the prescription of narcotics .
Narcotic legislation allows heroin prescription only for scientific purposes .
A research plan was set up, first projects were started in early 1 994. At present, seven projects in six cities have been implemented The research protocol and preliminary results are presented. This is a version of a paper presented at the Vlth Intemational Conference on the Reduction of Drug Related Harm in Florence, March 1995. By 1994 there were 204 residential treatment centres. Methadone prescription, originally accessible without formal restrictions, became regulated by law in 1915.