Forgetfulness, lack of interest and simply not getting around to it have been revealed as the most common reasons for not voting in the past two general elections.
Statistics New Zealand revealed 21 per cent of people who didn't vote in the 2011 election "didn't get round to it, forgot or weren't interested".
A further 7 per cent didn't vote because they felt they wouldn't make a difference, findings from the New Zealand General Social Survey showed.
The disillusioned group had nearly doubled since the 2008 General Election, Stats NZ spokesman Philip Walker said.
Age, income, and migrant status also made a difference to voting behaviour, the survey revealed.
Younger people were less likely to vote, with 42 per cent of people aged between 18-24 saying they didn't vote in the last election.
"People who feel they don't have enough money to meet their daily needs are also less likely to vote," Mr Walker said.
People's residency status also played a role.
Recent migrants had low voting rates, while migrants who had been in New Zealand for longer periods had very similar voting behaviour as people born in New Zealand, Mr Walker said.