The Army Bomb Disposal Unit was called to a St Vincent de Paul charity shop in Terenure, Dublin after a donor handed in a box of antiques that contained a grenade.
The bomb disposal unit examined the weapon, which was not found to be viable.
The Defence Forces were called to the shop in Terenure at about 4pm on Thursday and were supported by local gardaí.
It is believed the donor handed over some furniture to the shop, sparking the alert.
