Cincinnati-based P&G made the false claims but not willfully.
The verdict capped a two-week trial in which Playtex accused the consumer products giant of falsely claiming that its product, Tampax Pearl, provided superior comfort, protection and absorbency over the Playtex Gentle Glide tampon.
Playtex lawyer Jeffrey A. Schwab asked Judge William H. Pauley for a court order blocking P&G from continuing to make the claims in its advertising. The judge said he would consider the request next week.
"I would suggest there's some urgency in this matter," Schwab said.
P&G spokeswoman Elaine Plummer said the company was studying its appeal options.
"The most meaningful verdict is the one women make after they have tried Tampax Pearl, realize it is superior to the leading plastic, and then purchase more. That decision is handed down every day by thousands of women at the store shelf," she said.
In a statement, Playtex Chief Executive Officer Michael Gallagher said the case had always been "about truth and fairness" for the Westport, Conn. company.
"It is regrettable that Procter & Gamble had to resort to false advertising. Now that the jury has spoken, we expect that P&G will compete fairly and truthfully in the marketplace. We look forward to that challenge and are confident we will succeed," he said.
Schwab had told jurors that P&G made the false claims because it knew that tampon customers rarely change products unless they are told that a competitor's brand provides superior protection.
P&G's attorney, Harry P. Weinberger, had argued that the company's product was superior and that the advertising claims were not false. He accused Playtex of trying to win in the court what it was failing to win in the marketplace.
Playtex had portrayed its quest as a David and Goliath-type fight against P&G, which is 50 times larger than Playtex.
Playtex has annual sales of $800 million and says it controls about 30 percent of the tampon market. It says P&G, with annual sales topping $60 billion, has about 40 percent of the tampon market.
In a counterclaim, P&G had argued that Playtex was falsely advertising that some of its tampons were "so comfortable that you can't even feel them." The jury rejected that claim.
In court papers, P&G said Tambrands introduced Tampax tampons, the first tampons, in 1936.
P&G bought Tambrands in 1997 and spent more than $110 million researching and developing a plastic applicator tampon to compete with Playtex. Playtex had dominated the plastic tampon market since it first introduced its product in 1968.
In closing arguments Thursday, Playtex lawyer Matthew B. Lehr has asked the jury for as much as $14.55 million in damages.
After the verdict, he called it a "great day for Playtex."
"It wasn't about the money," he said.
In trading on the New York Stock Exchange, Procter & Gamble shares rose 22 cents to close at $89.80 while Playtex shares gained 2 cents to $7.67.