More than 18,500 Britons travelled by campervan that year, renting 9090 vehicles for an average of 18.3 days each.
They pumped a total of $81.1 million into the New Zealand economy during their travels - $4380 per person.
Tourism Holdings spokeswoman Kate Meldrum, who represents campervan rental brands including Maui, Britz, Kea and Mighty, said word of mouth in the UK had helped build New Zealand's reputation as a great place to travel in that way.
"That just permeates then through UK society, basically - it becomes a standard thing that when you go to New Zealand, it's a must-do."
Ms Meldrum said people were attracted to the convenience and freedom of camper vans.
"Travelling around New Zealand by campervan is obviously an easy thing to do because you want to see the whole country, which you can do comfortably in say three or four weeks if you're on a road trip.
"It's the easiest way to get around because you just don't have to pre-book anything - you literally point the nose of the camper van in the direction you want to go, and off you go.
"It gives you that sense of freedom, and I think that's what is so delightful about the experience in people's minds."
Australians are the top campervan users in New Zealand, accounting for 29 per cent of all rentals, followed by New Zealanders at 16 per cent and Britons at 14 per cent.
Germany followed at 10 per cent and the Netherlands at 3 per cent. Other Europeans made up 15 per cent of the market.
International rental van users spent a total of $447.9m in New Zealand in 2011.
Australians spent less than their British peers, pumping $2939 per person into the economy compared with $4380 per person, while the Dutch were the biggest spenders, pumping $5330 per person into the economy.
The UK survey was conducted on behalf of clothing company Helly Hansen.
