Fingerprint scanners are being used at two Kent nursery schools to check the identity of parents.
Springfield Lodge Day Nursery, which has sites in Dartford and Swanscombe, is scanning the prints each time parents drop off their children.
Linda Berryman, the owner of the nursery, said the measures were for the "safety and security" of the children.
But the charity Kidscape, which aims to protect children from harm, described the measure as "paranoid and overkill".
Michelle Elliot, director, said it gave the wrong message to youngsters.
She said in reality of the 11 million children in the UK, on average seven to 10 were abducted and murdered each year.
'No information recorded'
"But we don't want to give children, particularly young children, the idea that the world is so dangerous that they can't even go to nursery school without being scanned."
Ms Berryman said parents at the nursery were happy with the heightened security measures.
She said it made life a lot easier for parents when dropping off and picking up so that they were not hanging around waiting for their children.
"There is no actual information recorded, only the information that we've already got," she said.