"The night before at Versailles, Khloe drank a little too much," Kim said on "Jimmy Kimmel Live."
Kim said Khloe, 30, was so hung-over that she was still asleep while getting her makeup done that morning.
"I had to wake her up and she was laying down sleeping getting her makeup done for the wedding," Kim, 33, added. "I was like praying she'll get up in time to walk down the aisle! ... She was so hung over."
She added, "I think everyone just had such a good time at Versailles, they just drank way too much."
Kardashian also opened up about having the wedding celebration in two countries, with the rehearsal dinner May 23 in Paris and the actual wedding in Italy May 24.
"We tried to trick everyone," she said. "We really wanted to surprise everyone and just tell them that they've all been fooled and it's really in a different country ... some people had no idea."
Even though Khloe might have gotten a little too inebriated, Kim said the wedding was a dream come true.
"It was the most amazing experience, just to be able to share that experience," she said. "We kind of wanted everyone to be on this love journey with us, because we fell in love in Paris, then I got pregnant with our daughter in Florence. So we kind of wanted to share our love story with all of our friends and family."