The man tried to lure the 12-year-old Hartford Manor Primary School pupil into his car after claiming her mum had sent him to pick her up at around 3.30pm last Tuesday, July 7.
The man, thought to be aged 20-30, is described as being around 5ft 7ins tall and of slender build, with a shaved head. He has a ‘pale complexion’, speaks with a local accent and was wearing a green shirt and light blue jeans.
A police spokeswoman said: "After telling the girl he was there to pick her up from school, the man invited her into his car, which is described as a dark 4x4.
"The girl refused and the man left the area."
Insp Paul Loughlin, head of the Northwich Neighbourhood Policing Team, said: "We are very concerned about the behaviour of this individual and ask that parents and schoolchildren be aware of anyone acting suspiciously near school areas and to contact police to report any such activity.
"We have increased patrols and anyone with concerns should contact us."
Anyone with information which could help the Northwich CID officers investigating the incident can call 01244 613254, or CrimeStoppers anonymously on 0800 555111.