Marks & Spencer says Brexit means there are delays in some items reaching its Irish stores.
Customers at several of the British chain's Irish stores have been greeted by partially empty shelves and fridges in recent days.
It is understood some products have been delayed coming into the country due to the new travel requirements facing hauliers transporting goods.
Products with a short shelf life - such as vegetables - will be impacted the most during this initial period, as well as some refrigerated goods.
In a statement, an M&S spokesperson said: “Following the UK’s recent departure from the EU, we are transitioning to new processes and it is taking a little longer for some of our products to reach our stores.
"We’re working closely with our partners and suppliers to ensure customers can continue to enjoy the same great range of products.”
Some M&S stores in France are also reported to be out of certain stock - such as sandwiches and salads - due to the impact of Brexit.
Managing Director of Retail Excellence, Duncan Graham, says some teething problems were expected after the transition period ended.
He said: "In terms of what's on display on the shelves of food stores at this moment in times... that's where it's most noticeable.
"I think you have to go back to perhaps the organisation of some of the UK supply base, rather than what's happened at retailers in Ireland."
It comes as online shoppers potentially face additional charges when ordering online from retailers based in the UK.