A thief broke into a Kellyville yard and stole aluminium pool fencing and windows, copper and flagpoles, between 3pm on Friday and 6.30am, Monday.
A witness told police a man and a vehicle were in the yard on Friday.
The man was described as Caucasian in appearance, 25-30-years-old, of stocky build and with short brown hair.
The vehicle was described as a white tilt tray Isuzu truck with blue stripes on its side. Possible first letters of the registration could be ''TT''.
If anyone has any information about this theft please contact Castle Hill police on 9680 5399 or Crime Stoppers on 1800 333 000.