A man in his 30s has been arrested after four machine guns, ammunition and silencers were seized.
The weapons haul was recovered as part of a Garda sting operation on organised crime gangs in Dublin.
The seizure, which included Ingram sub-machine guns, magazines and four silencers, was made at an industrial estate in Mulhuddart in the north of the city.
The arrested man was detained at the scene and taken in for questioning under section 30 of the Offences Against the State Act at Kevin Street Station.
A Garda spokesman said all the weapons were recovered in a unit in the Damastown industrial estate.
The guns will undergo further ballistic tests.
A number of other searches were also carried out in the south inner city.
The operations were carried out by detectives based on the southside backed up by the elite Emergency Response Unit.