Kiwi women are earning $4.09 less than men on the average hourly wage, according to newly-released income figures from Statistics New Zealand.
The Council of Trade Unions (CTU) says that means women earn $163 less than men in a 40-hour working week.
The figures show the gender pay gap has risen to 12 percent in the June 2016 quarter, compared with 11.8 percent in the June 2015 quarter.
It means we're not getting any closer to pay equality, the CTU says.
"The Government has a duty to show leadership and take action," CTU President Richard Wagstaff says.
"Women must be paid fairly. For as long as there is a difference in pay based on gender we have a serious issue of unfairness.
Minister for Women Louise Upston says she's disappointed to see the gap increase.
She says employers need to focus on tackling the barriers that prevent women from advancing their careers, and ensure women are fully valued for the work they do.
"We know that leadership from the top matters. It is crucial that employers examine their own processes and take action to correct any gender pay gaps."
Ms Upston also says the public service needs to lead by example.
"The Ministry for Women is working with the State Services Commission (SSC) to address gender pay gap issues in the public service," she says.
But the Green Party says the Government needs to take more action on the issue.
"Just four years ago, the gender pay gap had gone down to 9.1 percent but the trend now seems to be a gradually increasing gap between what men and women are getting paid in this country," Green Party women's spokesperson Jan Logie said.
She called for Cabinet so sign off on recommendations from a joint working group into gender pay equality that was set up in 2015.
The Joint Working Group on Pay Equity Principles' recommendations were signed off by the CTU, Business New Zealand, MBIE and the State Services Commission and sent to ministers in May for consideration.
They proposed the Government set up a process for addressing pay equity claims.
NZN / Newshub.