More than a third (35 percent) of parents are concerned about direct advertising through mobile phones and the effect it has in encouraging children to grow up too quickly.
Research conducted as part of the 'Bailey Review of Commercialisation and Sexualisation of Childhood' also revealed that while parents believe their children should own smartphones for both safety and social reasons, ithe devices also offer easy access to inappropriate website including pornography.
Nearly nine in ten (88 percent) of parents said their children are being forced to grow up too quickly.
"Parents are telling us in no uncertain terms that they are worried about the pressures on children to grow up too quickly," said Reg Bailey, who is carrying out the review, which was commissioned by the Department of Education.
"They are also uneasy about marketing to children through new digital media. It is clear that their concerns have not been created out of a moral panic but from their everyday experience."
The full review is due out next month.