Vandals sprayed paint on the sides of dozens of cars parked in Ifield.
A Sussex Police spokesman said 30 to 40 vehicles were painted along their sides in Ifield Drive between the Parham Road junction and Ifield railway station between 10.30am and 10.45am on Thursday (April 10).
The spokesman said the spray-paint, which appeared to be creosote paint, could be removed using white spirit.
Anyone with information was asked to contact police on 101 quoting serial 0555 of 10/4.