"That was super not okay. That was really unacceptable and manipulative. I was scared."
The Black Swan star's claim come after more than 50 women have accused Harvey Weinstein of sexual harassment and assault abuse and a string of other Hollywood stars have become the centre of allegations they took advantage of their fame to harass others.
Stars including Gwyneth Paltrow, Uma Thurman, Ashley Judd, Lupita Nyong'o, Heather Graham, Kate Beckinsale, Angelina Jolie and Cara Delevigne, all claim to have been the target of unwanted advances.
Portman said: "I think my first reaction when I heard everybody coming out was, 'Wow, I'm so lucky that I haven't had this.'
"And then, on reflection, I was like, 'Okay, I definitely have never been assaulted. But I've had discrimination or harassment on almost everything I've ever worked on in some way. I went from thinking I don't have a story to, 'Oh wait, I have 100 stories.'
"I think a lot of people are having these reckonings with ourselves of things we just took as part of the process."
The Star Wars actress believes the Weinstein scandal will change Hollywood forever and for the better.
She said: "There are so many things that we took for granted as part of our world. A lot of things that we just kind of put up with for reasons of maybe just being numb to it. But if you spent all your time reporting what was going on, that's all you would do as it's so pervasive. And yeah, it gets so built into the power struggles in every industry."
Portman said sexual discrimination between women and men was ingrained into the film industry.
"When I promote a film, I have to wear fashion on a magazine cover. A man is in a white T-shirt and jeans on a magazine cover - even that is a form of discrimination.
"That's a small thing that is not in any way comparable to the accusations of assault, but I think every woman has experienced discrimination. People commenting on my body all the time to me, from the time I was a child.
"It was a very comfortable environment for discrimination, where it's not something I ever thought was reportable."
- Bang! Showbiz