Villaraigosa said on Wednesday that the current number of 800 or 900 dispensaries is too high.
His comments come as the City Council works on guidelines for a long-awaited medical marijuana ordinance. They have suggested capping dispensaries at between 70 and 200 and allowing reimbursement at those clinics for "actual expenses."
The council will take up the issue again Dec. 2.
Villaraigosa must approve the ordinance for it to take effect.
Hundreds of dispensaries have opened in Los Angeles in the last few years. In 1996, California voters approved a measure that allows medical use of pot.