Around six police cars were sent to the scene at the Eyton Stores Spar in Eyton Road, Dawley, after the male member of staff was attacked just after 2pm on Wednesday.
An air ambulance also landed nearby but the man was said to have suffered minor injuries and was taken to hospital by road.
Officers remained at the scene three hours later where police tape cordoned off the entrance to the Spar.
Neighbours nearby did not see what happened in the shop but were perturbed by a large police presence shortly after 2pm.
A man who lives near the shop said that police vehicles attended "en masse" and were accompanied by both land and air ambulances.
One other woman said she counted at least eight police vehicles.
Meanwhile over in Wellington, a large part of the town centre was cordoned off throughout the day but police are yet to confirm the details of the incident.
A West Mercia Police spokesman said: "Earlier this afternoon police were called to Eyton Stores in Eyton Road, Dawley, after a man threatened a member of staff.
"A man has been arrested and is currently in custody."
The force has not yet confirmed what crime the suspect was arrested on suspicion of.
A West Midlands Ambulance spokeswoman said: "We were called by the police at 2.14pm to reports of a stabbing in Eyton Road, Dawley, Telford.
"An ambulance, paramedic officer and the Midlands Air Ambulance from Cosford attended. Crews arrived to find a man who had suffered minor injuries and was taken to hospital by land ambulance for further checks."
Any witnesses are asked to contact police quoting reference number 00327I.