Police are appealing for witnesses after two masked men carrying baseball bats robbed the Farmfoods supermarket in Quedgeley.
It happened at the shop on Bristol Road just after 10pm on Friday.
The men dragged two members of staff into a back office, where another employee was told to open a safe.
The robbers then put over £1000 into a black holdall and left.
They are described as around 5ft 8ins and 6ft tall, both of slim build and wearing dark clothes.
Anyone who witnessed suspicious activity in the area or with any information about this crime is urged to call 101 immediately, quoting incident 518 of June 14.
Alternatively information can be given anonymously on 0800 555 111, or via www.crimestoppers-uk.org. In some cases Crimestoppers offer rewards of up to £1000 where information leads to a conviction.
