Kim and Nicole, who went to school together, are 13 years old in the photo and are holding their thumbs up at the camera.
Both girls are beaming and Nicole is sporting a set of braces on her teeth.
Uploading it to Twitter, Kim commented: "#ThrowbackThursday @nicolerichie and I being oh so cool at 13 years old."
Nicole then retweeted the snap, adding: "Brace yourselves!"
Kim and Nicole both attended Buckley School, which is an independent school in Los Angeles. Paris Hilton and Kimberly Stewart were also in their circle of friends.
Although the girls don't really hang out together any more, it appears from their tweets that they are still in contact.
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