As in most countries of the world, Belgian law defines a whole series of substances, qualified as “drugs”, the use of which is prohibited and repressed. Originally conceived as a measure of public health, this ban is now being questioned by a growing number of health professionals, social workers, and even magistrates and police officers. Not only does it fail to achieve its objectives, but it is also blamed for a whole series of perverse effects. The alternatives to prohibition are little known and often confused. This booklet therefore takes stock of the simplest of them, namely the decriminalization of drug use: why, how, for what purposes?