The hold-up took place at the Aldi supermarket in Santry, north Dublin.
A garda spokesman communicated that three males entered the main premises at 2pm on Saturday afternoon fraying hoodies and scarves.
They were armed with a wheelbrace and a metal bar and cowed staff before making off with an undisclosed sum of cash.
No injuries were on.
Anyone with information is asked to contact Santry garda appoint on (01) 666 4000 or the Garda Confidential Line on 1800 666 111.