The country continues to trade at a surplus but export growth is slowing, with official figures showing a surplus of $534 million in April.
Exports rose 14 percent to $4.5 billion last month compared with the same period a year earlier, due to higher prices for milk powder, butter and cheese.
But Statistics New Zealand said April was the first month since August 2013 when exports did not hit another record high. Imports rose 5 percent to $4 billion.
China cemented its position as New Zealand's top trading partner, with exports to Australia, the United States and Japan all slipping.
ANZ Bank senior economist Mark Smith said export volumes of dairy products declined, and prices were starting to decline.
"Commodity prices have peaked a few months ago, and now we're starting to see it flow through in terms of the export position.
"Looking through at the generalised export basket, we did see fairly sharp falls in terms of dairy particularly ... but there are also some parts of the export sector that are starting to come off as well."
On an annual basis, the country posted a surplus of $1.2 billion, a turnaround from the previous year's $687 million deficit.