Almost nine out of every 10 UK parents say children are having to grow up too early, with nearly half unhappy with pre-watershed TV, a survey suggests.
The research is part of a government-commissioned review into the sexualisation of children, conducted by Mothers' Union head Reg Bailey.
Most parents said music videos and celebrity were encouraging children to act older than they were.
Mr Bailey is due to publish a full report in May.
Of the 1,025 parents of five- to 16-year-olds surveyed, 40% said they had seen things in public places, such as shop window displays and advertising hoardings, that they felt were inappropriate for children to see because of their sexual content.
And 41% of parents said they had seen programmes or adverts on television before 9pm that they felt were unsuitable for similar reasons.
The review is also conducting focus groups, and Mr Bailey said emerging areas of concern included adult-style clothing aimed at young children, as well as toys and games they felt were inappropriate.
Parents were "struggling against the slow creep of an increasingly commercial and sexualised culture and behaviour, which they say prevents them from parenting the way they want", he said.
He said parents "had little faith in regulators or businesses taking their concerns seriously", but also were put off complaining be fears they would be seen as "prudish or out of touch".
The review is exploring whether the should be restrictions on retailers selling sexualised products aimed at children - such as "Porn star" T-shirts or padded bras.
A code of conduct on "age appropriate" marketing and a new watchdog are among plans being considered by the review.
Items that have been criticised include pencil cases and other products with the Playboy logo.