No-one was injured during the armed robbery, which took place in the Altstetten district at around 9.20am, police said.
City police issued photos of the suspects caught on a video surveillance camera.
One of them, a dark-haired man with a beard and a moustache, is seen wearing sun glasses and a brown jacket, with blue jeans and a blue t-shirt.
He is around 170 centimetres tall with a powerful physique, police said.
The other man was masked, wearing a grey hooded sweater, dark pants with cargo pockets and black shoes.
Police said he is 175 to 180 centimetres tall and was wearing a black mask.
Both men reportedly spoke broken German with a slavic accent, the Blick newspaper reported online.
The police, who arrived on the scene shortly after the man made their getaway, are looking for witnesses.