Only 24 percent of board members on New Zealand's top 100 listed companies are women.
The survey of companies was carried out by Auckland University of Technology professor Judy McGregor.
She said progress towards having more women on company boards was glacial.
Last year, 22 percent of board members on top companies were women and in 2016 it was 20 percent.
Dr McGregor says the government, fund managers and the stock exchange need to take urgent action to make more progress towards diversity.
"I've been undertaking similar sorts of research now for 20 years and I could not have imagined that we would have been proceeding so slowly in the corporate sector," Dr McGregor said.
"So something is wrong and we need a step change now to fix it up."
Judy McGregor says 20 of the country's top 100 companies have no women at all on their board.