Qld medicinal marijuana trial to cost $3m

A trial of medicinal marijuana in Queensland will cost about $3 million, Health Minister Cameron Dick says.

Mr Dick admits the figure is a rough estimate because the details of the trial, set to begin next year, have not yet been worked out.

"I'm not going to commit money until we know the nature of the trial to be conducted. I think that would be foolish," he told a budget estimates hearing on Wednesday.

Queensland will conduct the trial jointly with NSW.