Revenue officers seized 20,000 cigarettes, 1.5 kg of tobacco and a car in which these were being transported when the vehicle was stopped and searched near Watergrasshill, Co Cork, on Tuesday.
In a follow-up search conducted at a house in Killarney, Co Kerry, and with the help of a detector dog a further 4.5kg of tobacco was seized.
Some €2,000 in cash which is suspected to be the proceeds of, or intended for use in, criminal activity was confiscated in accordance with proceeds of crime legislation.
In a statement Revenue said the smuggled cigarettes and the tobacco have a combined retail value of more than €14,000, representing a potential loss to the exchequer of more than €11,200.
A Croatian man in his 30s and an Irish woman in her 40s were questioned, and a file is being prepared with a view to prosecution.
The operation was supported by An Garda Síochána.