Officers from West Mercia Police followed a vehicle that had been cloned to the private lock-up where the operation was discovered.
Police say a significant amount of the vehicles have been confirmed as stolen while many broken-down car parts are being catalogued.
Three men, aged 20, 28 and 35 have been arrested and all remain in custody.
Detective Sergeant Kirsty Hill said: "Our search has so far identified more than 50 vehicles from all across the UK including from here in North Worcestershire with a significant number confirmed to have been stolen.
"We continue to search the yard and have also found a large number of broken down car parts which we are cataloguing now.
"Vehicle crime is not victimless. We all need our cars for work, for visiting loved ones and for our daily chores so for many people having their transport stolen is more than just inconvenient.
"As a result of our investigation so far, three men aged 35, 20 and 28 years old and all from the West Midlands have been arrested and are in police custody."