Thirty such signs have been put up on a road known for the harlots near Treviso.
The sign says "attenzione prostitute" meaning, "Watch out for prostitutes."
A local man found 35 prostitutes within a stretch of two miles.
"By night it's a sexed-up superhighway," he said.
Resident Dino Vezino, 34, said: "I saw this sign and had to slow down to get a proper look.
"Does it mean I have to look out for prostitutes crossing or that they are available around here?"