The star appears opposite Hugh Jackman as British aristocrat Lady Sarah Ashley in the movie, but Kidman admits she feels no pride for her work - because she "couldn't connect emotionally" to her character.
And she was so appalled by her own acting when she saw the film in full at its November premiere in Sydney, she and husband Keith Urban took the first plane out of the country so she didn't have to face the criticism.
Speaking recently on Sydney radio station 2day FM, she said, "I can't look at this movie and be proud of what I've done.
"I sat there (at the premiere) and I looked at Keith and went 'Am I any good in this movie?' But I thought Brandon Walters (an 11-year-old Aboriginal boy) and Hugh Jackman were wonderful. It's just impossible for me to connect to it emotionally at all.
"We ran because I didn't want to read anything. I didn't want to know."