The chicken chain introduced cows and the message 'Eat mor Chikin' on a billboard in 1995.
It's been so successful that Chick-fil-A has stuck with the campaign ever since.
The cow campaign plays off the idea that cows want people to eat more chicken so they will in turn not be eaten.
The Holstein cows appear on promotional material, including commercials, advertisements, and billboards, holding signs with different variations of the cow's request for customers to eat more chicken.
The company recently revealed the identities of the four cows that anchored the company's public image for the past 20 years in a video.
The cows caretaker, known as Cowboy Phil, has been working for Chick-fil-A for 18-20 years.
Phil explains that the process of teaching the cows tricks for advertisements can sometimes be difficult, but he loves it.
"Most tricks we teach, takes quite a while to do it," he says.
The cows are treated with patience and care and sometimes have to be trained on a daily basis to learn new tricks. This includes something that can seem as simple as sticking their legs out farther than they're used to. The cows are rewarded when they do tricks correctly.
"When we did the parachuting cows, we had like three weeks to get them comfortable," Phil says.
Check out the famous commercial:
Check out the full video below: