Italy raised 7.5 billion euros ($10.4 billion) on Thursday in a sale of 12-month bonds with the rate falling to a record low of 0.589 percent, the Bank of Italy said.
The rate at a similar auction on March 12 was 0.592 percent, the central bank said in a statement.
Demand was 1.36 times higher than the offer and the amount sold was the maximum planned, it added.
Italy's borrowing costs have fallen drastically in recent months amid increased investor confidence, allowing Prime Minister Matteo Renzi's new government to save money on interest payments from the budget.
The low rate for Italian debt coincided with a breakthrough return to medium-term bond markets by Greece on Thursday, in a major sign that the eurozone debt crisis is fading.