The duo starred alongside each other in the 1993 film Body of Evidence and Julianne has revealed how anxious she was before shooting one particular scene in which she slaps the music icon.
The 54-year-old actress recalled: "I was super nervous. I was so, so nervous."
"I didn't actually make contact. It was a fake slap, but she wasn't talking to me because she was being kind of method-y doing her thing so I felt nervous and scared. I didn't want to hurt her at all."
However, Moore admits Madonna's intimidating demeanour was confined to the film in which the singer's on-screen character, Rebecca Carlson, is suspected of having murdered her older lover for personal gain.
Moore - who also starred alongside Willem Dafoe in the erotic thriller - told Bravo's Watch What Happens Live: "She was [a method actor at] that time, because she was playing the girlfriend and I was playing the wife. We were supposed to be enemies. She's always been very nice to me other times. This was just on this movie, so I was very scared of her."