The record-setting spay/neuter event was held by FixNation and Spay-4-L-A.
The cats were brought in by people and rescue groups who have trapped the homeless cats. Four veterinarians and support staff went to work for four hours straight.
The organizations say there are up to 2 million feral cats in L.A. County and controlling their population is essential for their well-being.
"Unfortunately, there's not enough homes for the kitties, so we want to honor the lives of the cats that are here, but just make sure that they aren't making anymore babies," said Karn Myers, the co-founder and executive director of FixNation.
FixNation has done more than 225,000 cat sterilizations in L.A. County, including over 17,000 last year.