A teenager was followed on her way home from school in Crowborough by man driving a white van, said Sussex Police.
The 15-year-old was walking to Beacon Community College at 11.15am on Friday July 19 when she saw him driving slowly nearby.
The schoolgirl hid in a bush and then ran home and called police. The man did not get out of his van.
Sussex Police said the driver was white, of large build and in his 20s. He had short brown hair and was wearing a black vest top.
Sergeant Michael Keeler, of Crowborough Neighbourhood Policing Team, said: “There is nothing to suggest that this man was planning to commit any offences but it has left the 15-year-old girl very upset.
“We are keen to speak to anyone who can identify the driver so we can confirm exactly why he was in the area.
“Any reports of incidents of this kind are reported fully and I encourage anyone who feels that they are in danger to contact us.”
Anyone with information should call 101 quoting serial 646 of 19 July or the independent charity Crimestoppers anonymously on 0800 555111.