But the Planning and Land Use Management Committee also voted to allow small groups of patients and primary caregivers to grow their own marijuana, the Los Angeles Times reported.
The city had imposed a moratorium on dispensaries in 2007 but hundreds of new marijuana dispensaries have opened because of a loophole.
A lottery for permits approved two years ago to limit dispensaries should be revoked because it may violate federal law, City Attorney Carmen Trutanich said.
Last year, an appeals court ruled Long Beach, Calif., which started a lottery, was violating federal law by effectively sanctioning distribution of drugs.
A Los Angeles ban would be in effect at least until the California Supreme Court reviews the Long Beach case.
Councilman Jose Huizar, who represents Eagle Rock, where residents have complained about dispensaries, said he favors a ban.
Councilman Mitchell Englander said some dispensaries have brought crime and given the medical marijuana industry a bad reputation.
Medical marijuana advocates said a ban would limit access to marijuana for patients. The small collectives of three people that would be allowed under the ban would make it difficult for those who lack time or expertise to cultivate the drug, they said.
Advocates back a counter-proposal in which the city would ban most dispensaries but not take action against 100 that had opened before the 2007 moratorium if the dispensaries meet regulations limiting their locations and hours.
Councilman Bill Rosendahl said he supported the counter-proposal. Banning the dispensaries, he said, would drive the medical marijuana industry underground.
"To ban it would be totally insane and throw it right back into the back alleys," Rosendahl said.
The committee voted to move forward the ban and counter-proposal but all three of its members said they support a ban.