The Ministry of Health says the suicide rate has fallen by more than 27% over the past nine years.
A ministry report shows there were about 15 suicides per 100,000 people in 1998, compared with 11 per 100,000 in 2007.
This represents a drop of more than 27% from the 1998 peak of 577.
Suicide rates for men aged 25-29 have dropped by almost half since 1997, but men are still more than three times as likely to kill themselves than women.
The rate for people aged 15-24 is down 46% since 1995.
The number of people being admitted to hospital after intentionally harming themselves is down 25% since 1996.