Gardai seized drugs worth over €750,000 during raids on a number of houses in Ballyfermot in south Dublin on Monday.
The raids were part of an ongoing investigation into the sale and supply of controlled drugs in the area.
Cannabis resin, cocaine, MDMA and heroin with a total estimated street value of €758,000 was discovered by gardai.
Other drug related paraphernalia and documentation were also seized during the operation, Dublin Live reports.
One man has been arrested and remains in custody.
A garda spokeswoman said: "One man (early 30s) was arrested during the searches in Ballyfermot and taken to Ballyfermot Garda Station where he is currently detained under the provisions of section 2 Criminal Justice (Drug Trafficking) Act 1996.
"This man remains in custody and investigations ongoing."
