Three-quarters of girls who have sent explicit images to boys on their mobiles said the pictures were shared without their consent, the Daily Mail reported.
Girls can become distraught after regretting giving in to pressure to send explicit photos and videos of themselves.
Many girls see sexting as a normal part of growing up and are happy to perform on video and send the images to a boy, the charity said.
Two-thirds have no idea that sharing images of under-18s is technically illegal in the UK and that teenagers can be locked up for engaging in sexting.
Andrew Flanagan, chief executive of the National Society for the Prevention of Cruelty to Children (NSPCC), said he believed there was a link between sexting and the easy access of porn on the internet.
"There is a growing phenomenon among young people for taking and sharing sexually explicit photographs," Flanagan said.
"We have seen a significant growth in concerns about this issue from young people. Many girls report being constantly pressured by their peers for explicit photos and being absolutely distraught when these photos are passed round," Flanagan was quoted as saying by the paper.
Another charity, ChildLine surveyed 885 young people