The Aussie actress has never confirmed reports she has undergone cosmetic surgery - but Porizkova insists it's obvious she has had work done, and it's depressing that such a beauty had to go to such extremes.
Appearing on U.S. news show Access Hollywood Live on Wednesday (27Oct10), the retired model-turned-fashion blogger, 45, targetted Kidman for messing with perfection.
She raged, "She annoys me because I think that she was one of the most beautiful women ever and one of the greatest actresses; I really looked up to her.
"And when you start doing this (cosmetic surgery) to what already is beautiful... I guess that kind of insecurity really disheartens me because it makes me feel like, 'Well then, what about me? If you're so beautiful and you're so perfect and you need to change that to a different kind of perfection, where does that leave the rest of us?'"
Porizkova now urges Kidman to do the honest thing and let the public know her looks aren't all her own: "When it's so obvious - when you grow that big mouth... - why not admit to it."
The ex-model insists she has never gone under the knife - but, like so many aging beauties, she often considers it.
She adds, "I do nothing. I've done laser treatments, but I count that as nothing as technically it leaves you looking exactly the same... I've definitely had the desire (to remove wrinkles) and I battle with that desire on a daily basis because nothing ages as poorly as a beautiful woman's ego.
"I don't like to see it (youthful look) going away and I don't like this dragging down (of the face), and developing jowls and this weird neck thing, but it's age. At some point I've got to face it."