Its survey of 1,000 parents, part of an independent review of the commercialisation and sexualisation of children commissioned by the DfE in December, also found that nearly half of parents are unhappy with TV programmes or advertisements that are shown before the 9pm watershed.
Two thirds of parents had come across clothes, toys, games, music videos or other products that they thought inappropriate for the age group they were aimed at.
The full findings of the review, which is being led by Reg Bailey, chief executive of Christian charity Mother's Union, will be published by the DfE in May.
Focus groups conducted on behalf of the review have found specific areas of concern from parents, which include inappropriate clothing, sexualised content in music videos and pre-watershed TV shows, and peer pressure, whereby parents feel that they have to buy non-essential items for their children so that they don't feel left out.
Parents were also concerned that children are behaving in an overtly sexual manner before they are old enough to understand what their behaviour means.
Mr Bailey said parents are struggling against the 'slow creep' of an increasingly commercial and sexualised culture and that they feel let down by regulation and self-regulation.
He added, 'They are also uneasy about marketing to children through digital media. Almost all the parents thought it was inappropriate for companies to send phone and text adverts to children. They are particularly frustrated when sophisticated marketing techniques are used which they are unaware of and therefore unable to manage the pressure they create.'
Mr Bailey said parents feared being seen as prudish or out of touch if they complained.
He added, 'For us to let children be children, we need to let parents be parents. That means giving parents the support they need to help their children understand and resist the harms they face. But it also means putting brakes on ever-greater commercialisation and sexualisation facing children in modern society.'
