A man threatened staff with a knife during a robbery at a bookmakers in Burslem, Stoke-on-Trent, police said.
Staff at the Coral bookmakers in Hamil Road were forced to hand over a quantity of cash to the man during the robbery on Sunday morning.
No-one was injured, the man ran out of the front door and down Hamil Road towards Burslem, said police.
Detectives are studying CCTV footage from the area and are appealing for any one with information to contact them.
The robber was about 5ft 6ins tall, wearing a scarf over his head and dark glasses with a black hooded top. He was also wearing black gloves.