Central Statistics Office figures show the Live Register recorded a small monthly decrease of 400 last month.
This brings the seasonally adjusted number of people signing on in September to 435,200 - the lowest total in two-and-a-half years.
The CSO figures show that in unadjusted terms, a total of 429,335 people were signing on the Live Register last month, down 8,106, or 1.9%, compared to the same time last year.
The standardised unemployment rate was steady at 14.8% in September, unchanged from the August figure.
The figures also show that the number of long-term claimants on the Live Register in September rose by 9,379 (5.1%) to 192,778.
The number of long-term male claimants increased by 2.5% in the year to September, while the number of women claimants jumped by 11.9%.
They also reveal that in the year to September, the number of people aged 25 and over signing on the Live Register decreased by 0.3%, while the number of people aged under 25 fell by 8.9%.
The percentage of people aged under 25 on the Live Register stood at 17.2% in September 2012, down 18.5% from the same time last year and 20% in September 2010, as the level of emigration from the country continues to increase.
Commenting on today's figures, Merrion Stockbrokers' economist Alan McQuaid said that despite the fall in the Live Register figures, the labour market remains very weak.
''There is no easy fix to the unemployment problem, and things are unlikely to improve on the jobs front until the economy starts to grow again on a sustained basis. And with the global economy in a slowdown phase, the labour market is expected to remain under pressure for some time yet,'' Mr McQuaid said.
The economist said it will be a number of years before the jobless rate falls back into single digits.
