The Central Statistics Office has estimated that the volume of retail sales last year fell by just over 14% from 2008. This was the biggest drop in any year since records began in 1962.
The value of sales, which takes prices into account, showed an even bigger fall of 18%, showing that retailers cut prices in an effort to boost activity as the recession hit consumer spending.
Retail sales figures were particularly hard hit by a dramatic slump in motor sales in the early months of 2009. Though the falls in sales stabilised as the year went on, December's figures still showed caution among consumers.
For December alone, the volume of sales rose by 0.4% from November. But most economists prefer to focus on sales excluding the motor sector, and this figure actually fell by 0.9% from November.
The volume of sales in December was down 7.5% compared with December 2008, though this was smallest annual drop recorded in 2009.
There were monthly increases in most categories of sales in December, but almost all are still well down compared with December 2008.
The CSO said provisional figures for the final quarter of 2009 show an 8.2% fall in sales volumes from the same period in 2008, though sales rose by 1.6% compared with the previous quarter. The value of sales, which takes prices into account, was unchanged from November but down 12.5% from December 2008.