When asked on The Graham Norton Show on Friday about the work she's had done, she admitted she's had "a lot."
But when British TV host Norton asked her which one hurt the most, he got an answer he wasn't expecting.
"Having my vagina tightened," the 61-year-old admitted. "It was just excruciating."
When fellow guest Colin Farrell, who was sitting next to the mother of three, asked what it entailed, Osbourne hugged him and said, "I'll show you later."
The Talk cohost also discussed her 31-year marriage to Ozzy Osbourne, 64, and was candid about their problems earlier this year after the rehabbed rocker relapsed with drugs and drinking.
Osbourne sold all of her husband's cars when she learned he'd been drinking and driving, but he still didn't stop drinking, so she moved out. "[It was] the hardest thing I ever had to do … but I knew if I stayed it would have carried on."
Now that Ozzy's in a 12-step program, they have reunited.
"He says we're like bread and butter," his wife admitted. "We fit together so perfectly, we're as one. We're a team."