Nearly 500 females were newly identified as having been subjected to female genital mutilation (FGM) in one month, according to newly released figures.
The Health and Social Care Information Centre (HSCIC) said 467 patients treated at reporting acute NHS hospital trusts in England were found to have undergone the illegal procedure in September.
The data also showed that 1,279 female patients previously identified as having been subjected to FGM were being treated at the end of last month.
The findings are the first official figures to have been published on the numbers of FGM cases seen in hospitals in England, with 125 of the 160 acute hospital trusts in England returning data for September.
The HSCIC said the results were a "first step" towards understanding how many females have been subject to genital mutilation, but added that the data only included cases reported by acute hospital trusts.
HSCIC chairman Kingsley Manning said: "This is the first national collection of NHS data about numbers of FGM cases and we will continue to collect and publish these figures.
"Having accurate data about this crime is an important step in helping prevent its occurrence in the future.
"The information will support the Department of Health in their FGM prevention programme, and we hope to expand the dataset over time so that it provides a more complete picture across a wider variety of care settings."
Children's charity the NSPCC said the figures were "shocking".
NSPCC head of child protection operations John Cameron said: "These are shocking figures and prove that FGM is very much a live public health issue.
"This NHS data shows just how vital it is that health professionals are trained to spot the signs of FGM so we can ensure that women and girls who are subjected to this brutal practice get the post-traumatic support they deserve.
"We also need to make sure that information is shared amongst agencies when a victim is being treated for FGM so that other girls in the same family can be supported and protected.
"We need anyone who is worried about the thousands of women and girls in the UK who are vulnerable to FGM to call our helpline on 0800 028 3550.
"It doesn't matter if you're uncertain, we're here to talk things through and offer advice and you may in turn stop a child from being subjected to this barbaric practice."
Since launching in June last year, the NSPCC's FGM helpline has received 383 calls from the public and professionals with concerns about the practice, with 173 of these cases referred to the police and children's services.