ANZ senior economist Sharon Zollner says there is a risk that the New Zealand dollar will rise higher than the Australian dollar, hurting exporters.
New Zealand's terms of trade fell 2.6% for the June quarter, compared with a fall of 2.3% in the previous quarter.
That means fewer imports can be bought for every dollar of exports sold.
The price of New Zealand exports fell 1% in the period, while the price of imports rose by 1.7%.
Ms Zollner said the rise and fall of the dollar will be one of the main contributors to movement in export and import prices.
She said New Zealand commodity prices are outperforming Australian prices, and by extension, the New Zealand dollar should do the same.
