"In Belgium, a change in the law and a new prosecution directive were enacted in the first half of 2003. Cannabis was differentiated from other illicit substances, and the two concepts of problem drug use and public nuisance were introduced. The new status of cannabis allowed the public prosecutor not to prosecute if there was no evidence of problematic drug use or of public nuisance. After the Constitutional Court found that these concepts were insufficiently defined, a new directive issued in February 2005 called for full prosecution only in cases involving disturbance of public order or other aggravating circumstances. This includes possession of cannabis in or near places where schoolchildren might gather and also ‘blatant’ possession in a public place or building.
"For drugs other than cannabis, Belgian law punishes possession, production, import, export, or sale by imprisonment for between three months and five years and/or a fine. There is no separate offence of ‘trafficking’, but the term of imprisonment may be increased to 15 or even 20 years in the event of specific aggravating circumstances."

Source

European Monitoring Centre for Drugs and Addiction, Country Overview for Belgium (Lisbon, Portugal: August 2012), last accessed Dec. 14, 2012.
http://www.emcdda.europa.eu/p…