The gatherings were organised by a group, Bust Rape Culture Now, which comprises organisations concerned over the Roast Busters case, Xinhua reported citing a Radio New Zealand report.
The group demanded better funding for rape crisis centres, a focus on rape prevention and support for survivors.
A protestor from Auckland alleged that the police and the government have failed on women's safety. They should have taken much swifter action to investigate the case, Radio New Zealand reported.
Speaking from Sri Lanka where he is attending the Commonwealth Heads of Government meeting, Prime Minister John Key said he was not surprised by the turnout at the marches.
"The behaviour is just unacceptable on so many different fronts. The challenge I don't think for us as a country is understanding it, the real test is how do we make change to resolve some of these issues," Radio New Zealand quoted him as saying.