A shot has been fired during a hold-up at a western Sydney hotel overnight.

Two men armed with a firearm entered a tavern on Rooty Hill Road North, Oakhurst, about 11.30pm (Friday 19 April 2013).

The pair stole a sum of cash.

They then discharged a single round from the gun into the ceiling before fleeing the scene.

Police from Mt Druitt and Quakers Hill Local Area Commands responded to the incident.

A crime scene was secured and examined by specialist forensics officers.

None of the 30 or so staff or patrons who were at the hotel at the time was injured.

Local detectives have spoken with several witnesses but are seeking public assistance to progress their inquiries.