Shot fired outside house in Sydney's west

A shot has been fired outside a house in Sydney's west.

Police received reports at about 6.30pm on Saturday of a gun being fired in Palmyra Avenue at Lethbridge Park.

"When police and paramedics arrived, a number of witnesses were spoken to and a canvass of the area located a shell casing which will be forensically examined," police said in a statement.

There were no reports of injury.