The total number of smokers dropped between 2006 and 2009, a report shows.
The Tobacco Use in New Zealand survey found 21.8 percent of adults were current smokers in 2009, down from 24.4 percent in 2006.
A current smoker was defined as someone aged between 15 and 64 who had smoked more then 100 cigarettes in his or her lifetime and was smoking at least once a month at the time of the survey.
The survey had a sample of 5000 residents, with 1000 of the respondents targeted as Maori ethnicity, 500 as Pacific and 500 as Asian.
Of those who responded, 19.2 percent smoked daily.
Maori females were twice as likely to be smokers than females in the total population, at 49.3 percent compared to 18.9 percent.
Maori men (40.2 percent), Pacific men (32.2 percent) and Pacific females (28.5 percent) were also more likely to be current smokers than the total population.
Asian females (4.4 percent) and males (16.3 percent) were less likely to smoke.
Those living in the most deprived areas were more likely to smoke.
Youths aged 15-19 were less likely (18 percent) to smoke than the general population, a significant decrease since 2006 when the figure was 22.9 percent.
Maori youth and those living in deprived areas were more likely to smoke.
The survey found 6.4 percent of non-smoking adults were exposed to second-hand smoke in their homes in the week leading up to the survey, 6.1 percent were exposed to it in a car and 4.5 percent at work.
Maori non-smokers were more likely to be exposed to second-hand smoke than the general population.
Associate Health Minister Tariana Turia said the decrease in the number of smokers was great but the number of non-smokers exposed to second-hand smoke was a concern.
"We've made great progress in many areas but in the very place where our children are most vulnerable, we are still exposing them to serious harm."
Mrs Turia urged everyone to make their homes smokefree.