"When women's rights are under attack, what do we do? Stand up fight back," a crowd of 6000 people chanted as they marched through Melbourne's CBD as part of the global Women's March movement on Saturday.

Women, men and children marched against "misogyny, bigotry and hatred" from the State Library to Parliament House.

Following the tragic events in Bourke Street on Friday, the route for the march was changed "out of respect for the victims and their families" to avoid the mall altogether, an organiser said.

One of the three female organisers, Alana Dowdell, said they were "overwhelmed with the support we had", considering about a week ago they thought a few hundred would attend.