Activity in the manufacturing sector picked up sharply in May, helped by a recovery in the housing market and the falling New Zealand dollar.
The BNZ/Business New Zealand Performance of Manufacturing index stood at 55.7 last month - up 7.5 points from April.
A reading over 50 indicates the sector is expanding and the index is now back at levels recorded in February and March.
All five indices expanded, led by production and new orders.
But BNZ economist Doug Steel says that while the very strong rebound is encouraging, it is too early to draw conclusions about whether growth is here to stay, because there are still big international risks on the horizon.
He says recent trends in the PMI suggest the manufacturing sector made decent contributions to GDP growth in the first and second quarters of 2012.