The 54-year-old has admitted the loss of her father -- legendary rock manager Don Arden -- to Alzheimer's disease inspired the morbid agreement.
In her autobiography "Survivor: My Story - The Next Chapter", Osbourne describes how the hasty decline in her father's health -- she had been estranged from Arden for a number of years -- made her determined to protect her children from the same kind of anguish, reports contactmusic.com.
In the book's serialisation in The Mirror, she writes: "We believe 100 percent in euthanasia. So we have drawn up plans to go to the assisted suicide flat in Switzerland if we ever have an illness that affects our brains. If Ozzy or I ever got Alzheimer's, that's it -- we'd be off."
She revealed that her three children -- Aimee, Jack and Kelly -- all understand their parents' reasons for the death pact.
"I saw my father suffer from the day he came back into my life in 2002 to the day he died in July. There's no way I could go through what he did or put my kids through that," she said.
"My father deteriorated at such a rapid speed he became a shell of himself -- dribbling, wearing a diaper and tied into a wheelchair because he didn't realise he could no longer walk.
"Ozzy and I have asked our lawyers to make the appropriate arrangements. It's taken away some of the fear of our ending and is a final gift of love to our kids," she said.
Osbourne also reveals she has been taking anti-depressants for the last 11 years.