Republic's exports to the UK take a dive after Brexit
The Republic's goods exports reached a record last year of almost €117bn (£99bn), but exports to Britain dropped by almost half a billion euro as the Brexit vote took its toll.
Imports into the Republic from the UK also fell back by €1.36bn (£1.16bn).
The preliminary data from the Central Statistics Office marks the first official figures showing the impact of the Brexit referendum on the country's crucial export sector.
Exporting businesses, particularly in the agri-food sector and those in border areas, have been hit hard by the slump in the value of the pound in the wake of last June's vote.
Sterling at one point had lost almost a fifth against the euro as it tumbled to more than 90p against the single currency, putting a squeeze on small and medium-sized exporters as they grappled with the currency impact of the referendum.
Alan McQuaid, from Merrion Fixed Income, said that overall trade data for last year remained positive, although business and consumer confidence have been dented to some degree, though not in a major way, in recent months by the uncertainty surrounding Brexit.
"Still, the uncertainty over the implications of Britain's decision to leave the EU suggests risks on the external trade front remain elevated for 2017 and beyond, especially for food exporters," Mr McQuaid added.
"The movement in the euro-sterling exchange rate will be critical in this regard."
The news came as Food and Drink Ireland, the lobby group affiliated to Ibec, called on the Government to implement policy measures to ensure that the Irish agri-food sector remains innovative, competitive and capable of meeting the challenges posed by the Brexit vote.
"Ireland's largest indigenous sector faces substantial challenges in the years ahead in a world that has changed radically in 12 months," said Paul Kelly, director Food Drink Industry Ireland.
"On the international front, 2016 saw the risks from Brexit beginning to crystallise for Irish food and drink exporters."