The 26-year-old praised Thurman at the Elle Women in Hollywood event saying working with the actress was a "pretty crazy experience", reported E! Online.
"Working with Uma was a pretty crazy experience. Her role was someone more intelligent, more charming, wittier and better in bed than me. Which, was obviously very difficult to cast," Pattinson said.
"Rob, you're a real gentleman on and off the screen," Thurman gushed back.
The "Twilight" star was dressed in a gray suit, white shirt and tie. Pattinson's appearance was not publicized beforehand. Instead, he skipped the red white carpet and entered the event through a side entrance of the hotel.