Prices for commodity exports rose for the sixth month in a row to a 10-month high in January, due to stronger timber and dairy prices.
The ANZ Bank's commodity price index edged up 0.3% on the previous month, after a 1% rise in December.
The series has gained 8% since last July but is still 14% below its record high in April 2011.
Seven of the 17 commodity groups rose in price, three were weaker, and seven flat.
The biggest rises were for animal skins, logs, skim milk powder and butter, while the main products to fall were aluminium, beef and lamb.
The index is still 6.1% lower than the same month a year ago.