The number of people on the Live Register rose by 0.4 per cent in February to 171,394, according to the Central Statistics Office.
When seasonal factors are taken into account, the seasonally adjusted total rose by 2,000 from 167,000 in January to 169,000, the highest figure in three years.
The unemployment rate in February was 4.5 per cent. This compares with 4.2 per cent in April 2002, based on the Quarterly National Household Survey.
This month's change compares to an increase of 2,377 or 1.5 per cent for the corresponding month last year. In the year to February 2003 there was an increase of 9,057 or 5.6 per cent.
This compares to an annual increase of 10,741 or 6.7 per cent recorded in the year to January 2003.
In the month, the estimated number of casual and part-time workers on the Live Register was 8,642 males and 13,091 females.
The jobs market continued to feel the strain of economic decline last month, as redundancies remained well above levels recorded in 2002, it emerged yesterday.
The latest redundancy numbers from the Department of Enterprise, Trade and Employment show 4,264 people were laid off in the two months to the end of February, an increase of 6.1 per cent on the same months of 2002.