"I can't go to the Oscars because I'm going to have a knee operation," said Dench, who's a best-actress nominee for her performance in "Notes On A Scandal." She presented the movie Feb. 12 at the Berlin Film Festival.
"Don't put money on me, because you'll lose it," Dench joked when asked about her chances on Oscar night. She's up against Kate Winslet, Penelope Cruz, Meryl Streep and the heavily favored Helen Mirren. But whatever happens, she said, "I shall watch and cheer from my bed."
The six-time Oscar nominee won as best supporting actress for playing Queen Elizabeth I in 1998's "Shakespeare in Love."
She stars in "Notes" as a lonely, scheming teacher who discovers a younger colleague, Cate Blanchett, is having an affair with a 15-year-old student.
"I wouldn't want her around," Dench, 72, said of her character at a news conference. "She behaves appallingly."
Last year, Dame Judi was nominated for playing a very different — but nearly as formidable — woman from British history, Laura Henderson of "Mrs. Henderson Presents."
Laura Henderson was a rich widow who bought a theater and staged a nude revue for the entertainment of wartime London. In the process, she took on Germany's Luftwaffe and Britain's censors to keep her theater going through the devastating years of the blitz.
More from CBSNews.com on Dame Judi Dench and on the Oscars ...
"I think she was a nightmare, actually," Dench, who met some of the company's surviving showgirls to prepare for the role, told The Associated Press in an interview. "She didn't know anything about the theater at all, and interfered terribly. But she was the most extraordinary woman. She used to pay for weddings and birthdays, and would always be taking them food. I don't know how she got the food during the war, but I expect she had ways."