The New York Police Department (NYPD) predicts there will be fewer than 600 murders in the city this year, the lowest figure for 42 years.
There were 2,262 people slain in 1990.
"It's a mayor success story for the men and women of the department," NYPD commissioner Raymond Kelly said on Wednesday.
"You have to take the position that one more murder is one too many," he added.
The NYPD said there had been 536 murders since 1 January, down from 612 for the same period last year.
The number of reported crimes so far this year is six percent lower than for 2001 - partly the result of a police crackdown on drug offenders and the removal of their guns, police officials said.
'Zero tolerance'
New York's reputation for being safer than in the past is widely attributed to the success of former mayor Rudolph Giuliani's vigorous "zero-tolerance" campaign launched in the 1990s.
A booming economy is also cited as a reason for the city's declining murder rates.
Many US cities have seen similar drops in crime, although the trend is reversing in places such as Atlanta, Boston and Los Angeles, as the recession bites deeper.
There was a 3.1% rise in the national murder rate last year - the first increase in a decade.
The New York figures are good news for the mayor, Michael Bloomberg - especially as some police resources have been diverted to fight terrorism.
There had been speculation that the number of offences was actually rising, as many saw the mayor as a less aggressive crime-fighter than his predecessor, Mr Giuliani.
But although the city's overall crime rate is down, incidences of certain types of violence are increasing.
As of 1 December, rapes had risen by 5.5% from last year to 1,885, or about six a day.