New figures from the CSO show that seasonally adjusted exports fell by 5 percent, or €443m, between December and January. The total value of exports in the month was €8.35bn.
Seasonally adjusted imports decreased by €30m, or 1 percent - meaning that there was a decrease of €413m in the seasonally adjusted trade surplus, which came to €3.9bn in January.
Exports have increased on an annual basis by more than €1.05bn - an increase of 15 percent.
This increase has been driven by medical and pharmaceutical products - they were up by 26 percent (€425m). Exports of organic chemicals also increased by 18 percent (€298m).
52 percent of Ireland's exports went to EU countries, the United States was the next largest importer of Irish goods, accounting for just under a quarter of all Irish exports.
The corresponding figure for Irish exports to the US in 2014 was only 10 percent.