Officers are now appealing for information after the find at an industrial estate on New Road, Stafford.
Police were called shortly after 2pm on Thursday to reports of suspicious activity.
Officers attended and found a large-scale cannabis factory, with a total of 861 plants, with 285 of these in flower, as well as 100 heat lamps and dozens of transformers.
One man fled the scene shortly after the arrival of officers.
The power supply to the premises has since been isolated by Western Power Distribution.
Officers seized the plants and dismantled the equipment.
Sergeant Claire Goodridge, of Stafford Borough local policing team (LPT) said: "This was a significant discovery that has undoubtedly resulted in substantial disruption to the supply of cannabis in our communities.
"A special thanks to PC Rob Smith and Shift Three officers for their work to ensure this substance and its associated criminality is kept off our streets.
"Inquiries are ongoing and anyone with information is asked to get in touch.
"Contact us on Facebook, Twitter, or call 101, quoting incident number 364 of 28 July.
"Alternatively, contact Crimestoppers anonymously on 0800 555 111."