Legalised cannabis supporters will argue their case at a rally in Brisbane's CBD on Saturday afternoon.
Members of the Medicinal Cannabis Users of Australia will join the SEQ HEMP Embassy and the Queensland Council for Civil Liberties groups to protest proposed changes to the state's drug laws.
If changed, cannabis would be considered as dangerous a drug as heroin and cocaine.
A spokesman for Attorney General Yvette D'Ath said the minister accepted the recommendations of an inquiry into organised crime, which recommended all drugs be classified the same way.
"It means courts can sentence on the basis of the quantity of the drug and circumstances of the offending rather than the classification of the drug itself," he said.
Canadian activist Dana Larsen will also attend the rally to talk about her country's decision to legalise cannabis later this year.