But the suit doesn't provide figures for the allegedly watered-down alcohol content.
Nina Giampaoli and John Elbert, who reside in Sonoma County, California, are the plaintiffs who say they stopped buying Budweiser after learning of the alleged mislabeling, the suit said.
Their suit, filed last week in federal court in San Francisco, alleges violations of California's consumer protection laws and Missouri's Merchandising Practices Act.
"I think it's wrong for huge corporations to lie to their loyal customers -- I really feel cheated," Giampaoli said in a statement. "No matter what the product is, people should be able to rely on the information companies put on their labels."