Hamilton Township police released a sketch of the suspect.
He's believed to be about six-feet-tall with an athletic build and deep voice.
Detectives say he got out of a black sedan, possibly a Ford Fusion, and started following the 12-year-old girl on Christine Avenue between Steinert and Wegner avenues at 8:15 p.m., trying to talk to her.
She ran away and called home. The suspect fled the scene.
Neighbors Action News spoke with said there are a lot of children that live in the neighborhood, and hearing about this has them on edge.
"It makes me sick to my stomach, and to think that I was in my house, and maybe this little girl was running down the street and I didn't know," said Alice Wood who lives in the neighborhood on Christine Avenue.
There's a school on Christine Avenue, which also has neighbors concerned.
"Unbelievable, because there's a school down the street too, and it's a lot of kids around here now," said Cheryl Deveney who lives nearby.
Anyone with any information is asked to call police at 609-581-4080.