The blondes were named among the five worst fashion offenders dues to their "tacky affinity for fur".
PETA pokes fun at Hilton, who came in at number one, by joking, "Now we know what happens to all of Paris Hilton's cast-off pets!"
And the organisation's activists blast Rod Stewart's daughter, quipping, "What does Kimberly Stewart have in common with the remains of the animals who were killed for her furs? They're both spoiled rotten."
They add, "Kimberly and her best bud, Paris, are so clueless about animals that they should team up for a new reality show: The Simpletons."
PETA bosses have dropped Martha Stewart, Victoria Beckham and Alicia Keys off this year's Worst Dressed list after the trio became "animal-friendly turncoats" in 2005 by distancing themselves from fur.