The 61-year-old man was closing the Wing Fung Cash and Carry in Dundee's Whittle Place when he was approached from behind by the two men. They knocked him to the ground before making off with the cash.
The men ran north up Whittle Place and turned right into Liff Road, where it is believed a car was waiting to pick them up.
Officers are looking at the possibility the two men may have been in the grounds of Camperdown Park before the robbery and that the getaway vehicle was parked there.
Detective Inspector Kevin McMahon said: "The 61-year-old man was not injured but has been left extremely shaken."
The cash was in a black nylon briefcase, which also contained bank cards, cheque books and keys.
One of the men is described as 20 to 30, slim, around 5ft 10ins and wearing a dark grey hooded top with reflective markings.
The second man is also believed to be 20 to 30, around 5ft 10ins, slim and wearing light clothing, possibly a matching hooded top and bottoms.
Anyone with information can contact Tayside Police.