Some economists fear the Reserve Bank's forecast for inflation may be too optimistic.
The Reserve Bank held the Official Cash Rate at 2.5% on Thursday and dropped comments to raise rates about the middle of the year.
Instead, it stated the first increase was likely in coming months.
Economists are split over whether this means June or July.
The Reserve Bank expects inflation to remain within its target band of 1% - 3% over the medium term.
But ASB chief economist Nick Tuffley, fears the bank may not be taking inflationary pressures seriously enough.
Meanwhile, ANZ New Zealand chief economist Cameron Bagrie, is picking June for the first rate rise.
However, he says the Reserve Bank has indicated that any rate increases are likely to be small and spread out.
Mr Bagrie is tipping four rises, taking the OCR to 3.5% by October, before the Reserve Bank pauses to assess the effect.
