The Socialist Left (SV) Party spokesman Nicolas Wilkinson said the majority in the Storting (Norwegian Parliament) agreed to:
Stop punishing people who struggle, but instead give them help and treatment.
The law change means that drugs are still illegal, just decriminalised in terms of possession - which is now seen as a matter for treatment. Efforts will still be made to stop the sale of drugs.
The change comes in the wake of other decriminalisation attempts around the world - for example, in America; California, Colorado, Alaska, Maine, Massachusetts, Oregon and Washington all have more relaxed marijuana laws.
Spain has laws which allow for the private use of the drug, but public use remains illegal and is subject to a fine.