Statistics New Zealand released its trade data on late Thursday. New Zealand's trade surplus climbed to NZ$350 million in May from NZ$183 million in April. April's figure was revised up from a surplus of NZ$123 million.
Analysts had expected a deficit of NZ$100 million.
Exports fell 4.7% in May, driven by a 28% decline in milk powder, butter and cheese, while imports dropped 7.0%, driven a fall in crude oil and capital goods.