Use of the products sold online and at retail outlets have led to warnings from doctors, NSW Mental Health Minister Kevin Humphries said on Tuesday.
Mr Humphries announced that the state government will ban the products under existing legislation.
Synthetic cannabis has been sold under the brand names Kronic, Spice, Kaos, Voodoo, Mango and Northern Lights and have a cannabis-like effect when smoked.
They are known to impair a person's judgment, creating hazards when an affected person operates machinery or drives a vehicle.
"It is important to understand that these are not soft or recreational herbal products, they represent a real danger to an affected person's safety and wellbeing," Mr Humphries said in a statement.
He said he has discussed the matter with the state Attorney-General Greg Smith SC, who advised that the products could be banned under the NSW Drug Misuse and Trafficking Act.
Therefore, they would be prohibited under the same category as cannabis, heroin and cocaine.
Sale of the products will be banned from July 1, with retailers required to arrange for destruction of any unsold quantities after that date.
A ban on the use of synthetic cannabis will come into effect seven days later.
Western Australia has recently banned the products with other states and territories announcing that they too are considering outlawing synthetic cannabis.
