Three men armed with a firearm and a knife threatened staff at a store on Tyneside industrial estate before getting away with a quantity of cash.
The incident happened at Shoe City on the Sands Industrial Estate, in Swalwell, Gateshead.
Northumbria Police said three men wearing ski masks went into the shop on 23 January.
One of the men had a gun and another carried a machete-style knife.
No one was hurt, but staff were left shaken.
Police said the robbers went out through the back of the store and it is believed they then drove off.
Detectives want to hear from anyone who was in the area at the time, shortly before 1800 GMT.