There's been an "explosion" in the number of women and children playing rugby league, New Zealand Rugby League says.
"We've almost doubled numbers in the last two or three years in the women's game," chief executive Greg Peters said.
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There has also been "strong growth" in the number of children playing the game - nearly 1000 more since New Zealand co-hosted last year's World Cup, he said.
"Our challenge now is to retain those children through to their adult years."
Mr Peters credited the increase to the exposure from the World Cup and the successes of local teams.
"Having those matches on home turf, the Warriors performing well, the Kiwi Ferns performing well, it's all part of the story," he said.
"Of course we want the Kiwis to be successful and be the number one team - and the Kiwi Ferns the same in New Zealand - but we have the wider responsibility to put rugby league on so that more people play it."
Mr Peters said it was "really heartening" to see the Tongans response to the Tongan national team, Mate Ma'a Tonga (MMT), recently.
The passion the Tongan team brought to the game is what motivated the Tongan-stacked Marist Southern Under 10 team in Auckland.
"They work as a team and they play like a team," George Moa, 9, said about the MMT team.
"That's why they didn't lose games, only some," 7-year-old Tevita Taufu'i said.
Their coach Toni Vaotangi said he had also noticed a change.
"Before I used to have heaps of energy to say, 'Hey stop this stop that,' now I hardly do that this year because of the inspiring MMT players last year," he said.
Mr Peters hoped the momentum would only increase, especially in the regions.
"We've got a lot of work in front of us to build on the success that we have had and keep growing the game."