But despite getting closer to Newsom's goal of reducing litter 50 percent over five years, the mayor said it's not enough.
"A 19-percent drop in litter is great, but we should by no means rest on our laurels now," Newsom said in a prepared statement. "Litter is something that we can prevent and it's important that we all continue to educate others and each do our part to ensure that our city is clean and free of trash."
In addition to announcing the decrease in trash, Newsom also named the brands which make up the largest amount of litter, calling them the "Dirty Dozen."
The list included McDonalds, Marlboro, Starbucks, Wells Fargo, Burger King, Taco Bell, Safeway, Walgreens, 7-Eleven, the San Francisco Municipal Transportation Agency, Popeye's and Jack In The Box.
The findings were part of an 2008 audit by the Department of the Environment, which catalogued litter at 132 sites.
According to department findings, plastic foam or Styrofoam litter decreased 36 percent since last year but cigarette butts nearly doubled.
Muni showed the biggest improvement from last year's Dirty Dozen, decreasing litter by 77 percent, while Wells Fargo has shown the biggest increase. The audit also showed that 41 percent of branded cigarette butts were Marlboro.
Newsom also announced the launching of an anti-litter campaign that will use bus ads to educate residents about the negative impacts of littering.
