Many Asians in the UK are hiding behind a wall of silence when it comes to reporting child abuse
A survey carried out for the charity found 48% of British Asians polled would tell the authorities if they suspected a child was being abused.
Many said informing the authorities would "dishonour" the child's family.
It compares with a similar survey in 2005 which found 92% of the general UK population would inform authorities.
The survey for the NSPCC involved face-to-face interviews with 500 first, second and third-generation British Indians, Pakistanis and Bangladeshis in the UK.
Most said they would prefer to deal with suspected child abuse themselves rather than involve the police or social services.
And their reluctance to speak out is fuelled by fears that the child would be removed from their family, and because the authorities do not understand their religion and culture.
More than two-thirds of those questioned said they also feared that reporting child abuse would have a negative effect on the "honour" - known as "izzat" - of a child's family.
NSPCC Asian Helpline Manager, Saleha Islam said: "Child abuse happens in all communities and there is no evidence that it is greater amongst British Asians.
"However, cultural issues and the importance placed on family reputation could mean that it is being hidden away.
"Izzat means that family comes before the individual, but to keep children safe from abuse their interests must come first.
"We want to send out a message to the British Asian community that putting up a wall of silence will not protect children. It will only protect the abuser who will be free to abuse again."
Of those questioned for the survey, 37% said they have suspected a child was being abused, yet 42% of them did nothing about their concerns.
A quarter confronted the alleged abuser themselves, 24% telling a member of the child's family and 17% speaking to the child concerned directly.
About 4% did report their suspicions to the police, and 3% to social services.
Two-thirds of respondents also said they felt their community was not open to talking about child abuse.
Ms Islam said: "We need to tackle the stigma and fear attached to seeking professional help for family problems otherwise British Asian children will be denied the protection on offer to other children in our society.
"The community must take responsibility for changing any attitudes and beliefs that could be making their children vulnerable to abuse."
She added: "We would like to see the Government lead a public education campaign that will give the British Asian community the knowledge and confidence to overcome any barriers to reporting child abuse."
In 2001, the NSPCC set up a telephone helpline to encourage information from Asian people who suspect child abuse but may feel excluded by existing English-speaking advice sources.
Why do the British keep letting Asians into their country when it is obvious that many of them are incapable of assimilating?