The National Treasury Management Agency has raised €4bn through the sale of a seven year Treasury Bond.
The syndicated sale achieved a yield of 0.867%, according to the agency, with orders worth €5.75bn were received from 160 different investors.
The NTMA said the majority of bonds were sold to overseas investors, with 15% sold domestically.
Ireland is among the first euro zone countries to mandate banks to kick off their funding for the year.
Fully pre-funded for the rest of 2015, the NTMA plans to issue €12-15 billion of long-term bonds this year. It said last month it would include at least one syndicated issue.
As well as beginning to cover its funding requirements for 2016, Ireland needs to raise debt this year to finish refinancing the majority of its bailout loans from the International Monetary Fund.
The NTMA plans to use cheaper market funding to replace more than €18 billion of the money it borrowed in 2010 as part of a three-year bailout.
It repaid €9 billion last month to start reducing the cost of carrying national debt set to remain above 100% of annual economic output until 2018.
The agency also raised €3.75 billion towards making the first repayment by selling new 15-year debt at a record-low yield of 2.49% in November.
Barclays, Davy, HSBC, JP Morgan, Nomura and Royal Bank of Scotland were mandated as joint lead managers for the issue.