Anna Wurtzburger, 64, was reportedly told by the fried chicken company the cardboard buckets appeared to be full in commercials so the customer can see the product.
But Wurtzburger, who lives off Social Security and made the purchase as a rare treat, says the business is misleading customers.
She said the chicken should of been advertised in a dish if it couldn't be seen properly in the towering bucket, The New York Post reports.
Wurtzburger, of Hopewell Junction, Hudson Valley, New York, is said to have hired a lawyer and filed a lawsuit against KFC.
She also returned two gift certificates the company sent her to ease her disappointment.
“I came home and said, ‘Where’s the chicken?’ I thought I was going to have a couple of meals,” she told The Post.
“They say it feeds the whole family … They’re showing a bucket that’s overflowing with chicken,” the 64-year-old widow griped.
“You get half a bucket! That’s false advertising, and it doesn’t feed the whole family. They’re small pieces!”
KFC called the lawsuit “meritless”, The Post reported.