Substance use is emerging in Belgium. The 'typical user' starts at a young age. Polydrug use has become very common. Cannabis and alcohol are the most frequently used substances among the school population. Heroin and cocaine are the most frequently injected drugs. Sharing of injecting material and paraphernalia is reported to happen in half of the subjects injecting drugs. Substance use causes a lot of adverse organic, social and psychiatric events. Management of substance use consists of information, drug-free treatment and harm reduction, including substitution and maintenance programs. The management of care in Belgium differs between the regions.