Per data, more than 35,000 instances of sexual misconduct and violence on NHS property were reported in the previous five years.
Between 2017 and 2022, rape, sexual assault, groping, stalking, and abuse incidents were reported to the English health service.
The British Medical Journal and The Guardian gathered the information from 212 trusts and 37 police units.
One in five cases involved patients abusing other patients, although not all trusts gave a detailed breakdown.
Meanwhile, police recorded nearly 12,000 alleged sexual crimes on NHS premises in the same time period.
These include 180 cases of rape of children under 16, with four children under 16 being gang-raped.
The investigation found that fewer than one in 10 trusts has a dedicated policy to deal with sexual assault and harassment, and the BMJ reported they are no longer obliged to report abuse of staff to a central database.
More than half of these allegations (58%) involved patients abusing hospital staff.
Experts warned that the figures were likely to be a serious underestimate as they are often deterred from making such complaints.
Deeba Syed, from the Rights of Women helpline, told The Guardian: ‘Women tell us they are expected to continue to care for patients who are abusive or harassing without efforts to adequately safeguard them from further harassment.
‘We hear worrying reports of women feeling pressured into not raising formal grievances and instead being transferred to different departments or locations.
‘They tell us it is argued that this is more expedient than moving the harassing patient, despite victims feeling this is unsafe to others and a punishment on them.’
Latifa Patel, BMA workforce and equalities lead, also said she assumed NHS trusts without dedicated sexual safety policies are ‘sitting on huge numbers of unreported incidents’, which she describes as ‘a truly disturbing implication’.
The data also showed that 193 of the 212 trusts reported 10 or fewer staff-on-staff incidents between 2017 and 2022, though the BMJ and The Guardian said medics thought this was implausible.
In addition, more than 4,000 NHS staff were accused of rape, sexual assault, harassment, stalking, or abusive remarks towards other staff or patients during the period.
Only 576 have faced disciplinary action, the investigation found.
Navina Evans, chief workforce officer at NHS England, said: ‘The health service must be a safe space for all patients and staff and must not tolerate any sexual misconduct, violence, harassment or abuse.
‘NHS England has established a dedicated team to ensure people who experience violence and abuse are supported in the workplace, and there is greater provision of support for all victims and survivors.
‘All NHS trusts and organisations have measures in place to ensure immediate action is taken in any cases reported to them and I strongly encourage anyone who has experienced any misconduct to come forward, report it and seek support.’