Fake CDs and DVDs are expected to cost the film and video industry €80m this year.
The growth in piracy has put counterfeiting almost on a par with legitimate business.
Christmas is the busiest time for so-called under-the-counter goods, the quality of which varies widely.
The National Federation Against Copyright Theft is trying to convince people they are wasting their money.
They say the quality of the counterfeit goods is so poor it is not worth buying.