The Stockton Animal Shelter is throwing a "Find Your Valentine" party to mark the holiday.
About 200 dogs and cats are available for adoption, and shelter workers are hoping by the end of the day the shelter will be empty.
Adoption fees normally run about $100 but through February the shelter is waiving the charge while providing vaccinations, spay and neutering, and microchipping.
Shelter Director Phillip Zimmerman says the animals might be free but they come with a responsibility for their new owners.
"[We] just would like people to make sure that the person they are buying the animal for is somebody that wants the animal because we don't want the animal back here, we want the animal to go to a forever home," says Zimmerman.
Lisa Tucker lost a dog and hopes to replace it with one from the shelter.
"And this is the best place to come because they got no home," says Tucker.
Adoptathons like this event have significantly reduced the euthanasia rate....doubling the number of animals available for adoption.
Sacramento's Front Street Animal Shelter is running a similar special with $14 adoption fees for animals one-year and older, through the month of February.
Adoption fees are normally $85 for dogs and $65 for cats. All animals come spayed or neutered, fully vaccinated and microchiped.
More information about adopting a pet can be found here.