New figures show the volume of retail sales decreased by 12.7% in March when compared to February this year.
This is the largest monthly decrease since January 2009, the Central Statistics Office (CSO) says.
When the motor trade is excluded, the volume of retail sales decreased by 1.9% last month.
However a number of sectors saw a large increase in sales.
This included food, beverages and tobacco (excluding supermarkets) which grew by 17%.
Hardware, paints and glass saw sales increase by 13.3% - while pharmaceuticals and cosmetic articles saw an 8.8% growth rate.
The sale of electrical goods also grew by 5.9%.
However, when compared with February, a number of sectors saw the largest decrease in sales.
Sales in bars dropped by 53.1%, clothing, footwear and textiles fell by 49.2% and motor trades dropped off by 30.7%.
The sale of books, newspapers and stationery fell by 29.2% - while department stores sales dropped by 25.8%.
While online sales represented 4.3% of the total turnover - the highest online share since collection of this breakdown began in November 2018.
Except for motor trades, all sectors saw an increase in the proportion of online sales in March.
Last month, 15.3% of all electrical good sales were online - up from 12.9% in February.
While the proportion of online sales for department stores more than doubled to 10.1%.