The outstanding amount of debt securities issued by Irish firms and by the Government stood at €824.2 billion at the end of June.
That was down 9% on the figure at the same time last year, figures from the Central bank show.
Debt securities include government and corporate bonds and are issued at an interest rate based on the perceived ability of the borrower to repay.
In the 12 month period under review, the outstanding amount of debt securities for the banking sector fell by 5% to €71.3 billion with short-term debt down by 26%.
The total amount of outstanding debt securities for the banking sector across the euro area fell by 7%, reflecting continuing deleveraging in the banking sector.