The picture, a spoof of Dutch painter Johannes Vermeer's Girl with a Pearl Earring, was found on Hanover Place close to the city's harbor.
Young lady with a Pierced Eardrum joins an alert box as the model's hoop.
On Tuesday, the work was found with dim paint tossed over the base of the lady's face.
Banksy's last work in the city was Mobile Lovers, which showed up in an entryway in Clement Street in April.
A column broke out over who claimed it, with Bristol City Council contending the work was on its property.
Nonetheless, Banksy kept in touch with Broad Plain Boys' Club saying it was theirs and the club sold it to a private gatherer for £403,000.
In any case the unacknowledged graffiti craftsman's new painting is not the first to have been vandalized in the place where he grew up.
In 2009, red paint was tossed over Mild West on Stokes Croft inciting requires the piece - one of Banksy's most acclaimed - to be ensured with an agreeable plastic covering.
What's more months after the fact the Hanging Man, at the bottom of Park Street, was harmed with blue paint. Both pieces were effectively restored.
Be that as it may one work that couldn't be spared was painted near the Bristol Royal Infirmary.
The picture, offering a police expert rifleman going to be shocked by a kid blasting a paper sack, was painted over after dark paint pulverized the picture.
