Seven people have been arrested in a series of early morning drugs raids in the Barry and Ely areas.
Detectives say the raids were the result of a "prolonged and complex" investigation into a drugs line in South Wales.
Several address in both areas were searched and 'numerous' drug hauls and mobiles phones were seized during the operation on Thursday morning.
A spokesperson for South Wales Police said the force "has a zero-tolerance approach to drug dealing and this investigation is just one example of how we are tackling drug dealing in the community."
"We can, and regularly do, act upon the information provided to us by the public, so please keep it coming."
In Cardiff Bay, more than 60 people have been arrested in recent months during a crackdown on drug dealing in the Butetown and Grangetown areas.