Officers attended a property on Convent Avenue, South Kirkby, on Friday, where they had a warrant to search a property.
Two women, aged 39 and 49, two men, aged 41 and 29, and a 15 year old male were arrested on suspicion of possession with intent to supply a controlled drug.
They have all been released under investigation.
Enquiries are ongoing by the South Kirkby Neighbourhood Policing team.
Sergeant Dave Lockwood of South Kirkby NPT said: "After receiving intelligence from the local community we executed a warrant under The Misuse of Drugs Act and seized a substantial amount of Class A Drugs.
"We would always encourage members of the public to contact us if they have information about possible drugs supply in our communities.
"We will always investigate any information received and take the appropriate action to rid our streets of drugs.
"We would encourage anyone to report to Police any criminal activity they are aware of via 101 or online at www.westyorkshire.police.uk/contactus or anonymously by contacting the independent Crimestoppers charity on 0800 555 111."