West Yorkshire Police excuted a warrant at the Toss O'Coin pub in Penistone Road in Holmfirth earlier this week.
Inside, officers discovered a huge cannabis grow of more than 600 plants.
The grow could be worth as much as around £750,000 if harvested and sold on the streets.
Images posted on social media by officers show rooms full of cannabis plants, with a sophisticated set up to help grow them.
A tweet from West Yorkshire Police's Kirklees Rural team said: "Rural NPT and the Catch and Control Team have conducted a warrant at Toss O`Coin pub, Penistone Road, Holmfirth.
"Officers located over 600 cannabis plants which is a substantial amount of Drugs removed from the streets."
The pub closed down late last year.