The cigarettes were found in a shipping container that had arrived from Rotterdam
€4.5 million worth of cigarettes have been seized at Dublin Port.
Revenue officers uncovered 9.6 million cigarettes that arrived into the port on a vessel from Rotterdam.
They were found in a shipping container, said to contain "tyres".
The smuggled cigarettes were uncovered using Revenue's mobile x-ray scanner during routine profiling.
The "Excellence" branded cigarettes have a retail value of almost €4.5 million.
Revenue said it "continues to target the supply of illicit tobacco products with a view to disrupting the supply chain, seizing the illicit product and prosecuting those responsible".