Kids were able to play sports and take part in other activities.
The program also provided jobs.
"This is making a big, big difference," said Ken Franklin, a gang intervention worker. "It's bringing the whole community together and where we didn't know each other, now we do."
The program began in 2008 with eight parks. The Los Angeles Police Department said it has led to a drop in crime.
"In 2008, we had an 18 percent reduction in gang-related violence," said Guillermo Cespedes, deputy mayor of gang reduction. "These are some of the most volatile neighborhoods in the city."
The program has been so successful, the city hopes to expand it to 50 parks in the future.