Speaking about consumption of illegal drugs per se in Belgium is not a simple matter. In fact, the small size of the country is inversely proportional to the complexity of its institutional and political system, marked by a federalism which is moving apart through constant evolution. The article relates to the French-speaking part of the country. It does not pretend to cover the whole of the consumption of illegal drugs, but instead focuses upon certain specific features. The different ways in which drugs are used and political and health policies are briefly described. Recent trends in the consumption of illegal drugs forms the core of the article, particularly use within leisure settings (parties) and the pilot project of prescribing heroin under medical control at Liege. In conclusion, the mobility of people between being users and traffickers indicates the need to look more internationally.