Police say one of the men had a knife and used it to order staff at Coral, in Red Bank Road, to hand over money after going behind the counter, while the other stood as look-out at the door.
They both fled on foot with a ‘couple of hundred pounds’ of cash, emptied from two till drawers, as police were called to the scene.
Officers later arrested two men, aged 35 and 52, both from Blackpool, on suspicion of robbery.
They remained in custody this morning where they were due to be quizzed by detectives.
A spokesman for Coral said the two members of staff on duty at the time were not hurt but ‘understandably shaken’, and will be given support as ‘number one priority’.
“The Coral security team is assisting the team with their investigation,” he added. “We will also carry out a review of the security measures in the shop following this incident.
“Betting shop armed robbery is a serious crime that is punished by lengthy jail time and surely not worth risking for just a couple of hundred quid.”
A Lancashire Police spokeswoman said: “We were called at 8pm last night to reports of a robbery at Coral Racing in Red Bank Road in Bispham.
“A man entered the premises and threatened the employee with a knife and demanded cash. The other was stood at the door.
“Then they managed to make off with an amount of cash.
“Shortly after, two people were arrested.”