Activity in the manufacturing sector expanded for the 23rd month in a row in April, but at a slightly slower rate than in the previous two months as growth in orders from abroad hit a six-month low.
The Investec Manufacturing Purchasing Managers' Index, which posted its fastest growth in 15 years in February, fell to 55.8 in April from 56.8 in March.
The index has been above the 50 mark denoting growth since May 2013.
Earlier this week the Department of Finance raised the country's growth forecasts for 2015 and 2016, setting it up to remain the fastest-growing economy in the European Union.
Investec said the PMI's sub-index measuring new export orders slipped to 56.3, its lowest since October 2014 and from 57.9 a month earlier.
Irish exports, which jumped more than 12% in 2014, are set to grow by 7.6% by value this year, the Department of Finance said in its updated forecasts.
Investec Ireland chief economist Philip O'Sullivan said he was not particularly surprised by the slight moderation in April given that growth across the euro zone - an export market for over a third of Irish manufacturers - was a touch lower than in March.
"Looking ahead, while manufacturing firms based in Ireland are clearly upbeat on their prospects - as evidenced by rising headcounts and purchasing activity - we are a little cautious ahead of next week's UK general election," O'Sullivan said.
"If the outcome of that were to put sterling under pressure relative to the euro this will be unhelpful for the sector, as 16% of Irish merchandise exports go to the UK," the economist said.