Medical marijuana advocates want voters to consider the issue in November.
The issue could reach the ballot through the Legislature or through an initiative petition.
On Monday, a House panel heard a medical marijuana proposal that would regulate cultivation and dispensation.
Bill sponsor Dave Hinson, a St. Clair Republican, unsuccessfully introduced similar legislation last year. But this year, the issue would have to go to the vote of the people instead of being legalized through legislative action.
The Missouri Association for Prosecutors and the Missouri Sheriffs Association has raised concerns about enforcement.
Meanwhile, a group called New Approach Missouri has started to collect the 160,000 signatures needed to allow voters to consider the issue.