Staffordshire Police launched the appeal after the theft at the premises on Sandy Lane in Rugeley, which is believed to have taken place overnight between Sunday and Monday, April 25.
The force it has been informed by witnesses of two men unloading a mower similar to the one stolen near to Trent Valley in Stafford around 2pm on Monday, April 25.
Anyone with information is urged to contact Staffordshire Police by calling 101 or going onto Facebook or Twitter, quoting incident 578 of 25 April.
A spokesman for Staffordshire Police said: "Officers are appealing for information after a lawn mower, line-marker and trailer, worth a total of £12,000, were stolen from a commercial premises in Rugeley.
"The theft took place at some point overnight between Sunday and Monday at the site on Sandy Lane.
"Witnesses reported spotting two men unloading a mower, similar to the one stolen, near to Trent Valley in Stafford, at 2pm on Monday (25 April).
"Anyone with any information or relevant CCTV or dashcam footage of the area at the time of the theft are asked to contact us on 101, Facebook or Twitter, quoting incident 578 of 25 April.
"Alternatively, contact Crimestoppers anonymously on 0800 555 111."