Gardai made the discovery during a planned search of a premises in Lucan
Heroin worth an estimated €150,000 has been seized in the Lucan area of Dublin.
The discovery was made during a planned search of a premises at around 11pm last night.
A woman in her late 40s was arrested at the scene.
She is being detained at Ronanstown garda station under Section 2 of the Criminal Justice (Drug Trafficking) Act, 1996.
Gardaí said the operation was part of an ongoing investigation into serious criminal activity in west Dublin.