Preliminary Central Statistics Office figures for September show that seasonally adjusted exports decreased by 4% to €7.694 billion from the previous month as the world economy is starting to show signs of struggling.
The CSO figures also reveal that seasonally adjusted imports fell 4% to €4.44 billion.
It said this resulted in the seasonally adjusted trade surplus falling by 4% to €3.254 billion in September.
On an annual basis, the value of exports increased by 8% to €7.9 billion. The main drivers were a 22% increase in the exports of medical and pharmaceutical products and 25% rise in essential oils. Exports of organic chemicals decreased by 9%.
Today's figures show that the EU accounted for 56% of total exports in September, with the US the main non-EU destination accounting for 22% of total exports in the month.
Meanwhile, the value of imports increased by 10% to €4.435 billion on a monthly basis. Imports of petroleum and related products grew by 40% and specialist machinery soared by 148%.
According to the CSO figures, the EU accounted for 60% of the value of imports in September, with 29% coming from the UK. At 11% and 8% respectively, the US and China were the main non-EU sources of imports.
Weak global demand hit Irish exports in the past couple of years, particularly on the merchandise goods side.
But the performance in the first half of 2014 was strong, up 13.1% in volume terms. However, with signs that the world economy is starting to struggle again, particularly the euro zone, there are doubts as to whether Irish merchandise exports will do as well in the second half of this year.
Commenting on today's figures, Merrion economist Alan McQuaid said that the weak euro will be clearly beneficial for a huge exporting country like Ireland, as will the close trading ties with both the US and UK, two of the better performers on the global economic stage in 2014.
"Against that, the deterioration in the overall Euroland outlook will take some of the shine off Irish export growth," the economist added.
Although not as strong as 2014, Mr McQuaid said he sees Irish exports of good and services increasing by 5% in volume terms next year.
