AbstractNeedle Park in Zürich existed as an open air drug scene from 1986 until February 1992. Within this six year period the City Government, City Parliament, governmental and non‐governmental organizations implemented a wide range of permissive and restrictive drug policies, from extensive harm reduction to closing the park. Police statistics and several studies suggest that tolerating an open air drug scene can have unforeseen and unfortunate consequences. Low drug prices, lack of law enforcement and lack of social control seem to attract drug users towards the open drug scene and the increase in problems appears to have been more rapid than the increase in the population of addic