Kidman, 40, an expectant mother of two, spoke about her passion for ending abuse against women during a Tuesday news conference at the U.N. headquarters, People reported.
"I'm a mother. I have a child on the way. A lot of it is realizing the things that are wrong and (pondering) how can I contribute to help my children have a better life?" Kidman said.
Kidman, a goodwill ambassador for the U.N. Development Fund for Women, said physical abuse against women is the "most widespread human rights violation of our time."
Kidman said "one in three women will encounter violence in some way, shape or form against them in their lifetime."
"That's an extraordinary statistic. Yet do we ever hear it?" she added.