The National Debt increased by €1.6 billion during 2007, bringing the total to €37.6 billion.
However, the National Debt/GNP ratio fell from 24.1% at the end of 2006 to 23.6% at the end of 2007.
The figures were contained in the end of year results by the National Treasury Management Agency (NTMA), which manages the National Debt on behalf of the Government.
The NTMA said the National Debt is now equivalent to just over three months' tax revenue, compared to four months' at the end of 2006.
The agency said that when it was established in 1990, it took three months tax revenue just to pay the interest on the debt.
The chief executive of the NTMA, Michael Somers, said the agency had a very good year overall.
He said funds had not been dramatically affected by the credit crunch or turbulence in international financial markets.
Mr Somers also said that the National Pensions Reserve Fund, which is also managed by the agency, had done quite well this year.
He said given that the Irish Stock Exchange had fallen by around 26% this year there had been concerns that the fund could have ended up negative.
However, because just a small percentage was tied up in the ISE, the Pension Fund remained in positive territory.
