The two men played their game of pool at The Holly Bush in Edenthorpe - while sneakily bashing the side of the table that contained cash inbetween taking their shots.
Once the money container was sufficiently loosened from the table, they put down their cues and stole about £18 in coins before fleeing the pub.
A member of staff, who did not want to be identified, said: "They basically pretended to play pool while prizing the money box open.
"The pool table is a bit away from where the seating is, so is not in view of most of the customers. They knew what they were doing.
"We didn't know about it until we noticed the money was gone and then checked the CCTV.
"It is very annoying."
He said the incident happened at about 3.30pm on Saturday, October 14.
And bizarrely one of the men returned to the scene with another man on Tuesday evening.
The member of staff added: "Customers said they had seen them go in and check the pool table again. They were checking the place out. "
One man was described as white and was wearing a dark-coloured tracksuit and aged in his mid 30s.
The second man was described as Asian and was wearing a dark-coloured jacket.
Contact police on 101 with information.