In a shock twist to the first round of voting favourites South Africa - expected to at least make the final two - were eliminated, leaving New Zealand and Japan to battle it out for victory.
It will be the second time the World Cup has been held in New Zealand, who staged the inaugural event alongside Australia in 1987.
They had also been due to co-host the 2003 tournament with Australia before being stripped of the right by the IRB after a row over stadium advertising.
After announcing the result IRB chairman Dr Syd Millar said: "I'm confident that any of three could have hosted a successful tournament as all three bids were of the highest order.
"But I would like to congratulate New Zealand, a great rugby nation."
Jubilant New Zealand Rugby Union chairman Jock Hobbs said: "I want to acknowledge Japan and South Africa.
"It was a very tough day so we feel their disappointment. We thanks the IRB councillors and we won't let them down.
"Winning the right to host the World Cup is an enormous honour and great responsibility. We will honour that responsibility. It's a proud day to be a Kiwi."