Officials from the Revenue Commissioners are to attend the annual Bloom festival in the Phoenix Park to make sure all traders are compliant with tax law.
The Irish Times has reported that Revenue wrote to all exhibitors to tell them officials will be carrying out inspections today.
The tax man apparently attends a number of markets and fairs every year in an effort to manage the risks in the "shadow economy".
Revenue says these visits play a vital role in the promotion of tax compliance through public visibility.
Last year, the festival attracted over 110,000 visitors.
This year's festival, which runs in Dublin's Phoenix Park over the June Bank Holiday weekend, features 30 show gardens, over 120 Irish food and drink producers, cookery demonstrations, flower displays and almost 200 retailers.
Winning stands will be presented with their medals by President Michael D Higgins this morning.