Thirteen out of Northern Ireland's 15 accident and emergency departments will not prescribe the morning-after pill to all who request it.
The government says sex education has improved
A BBC Newsline investigation found only two hospitals, Antrim and Craigavon area hospitals prescribed the emergency contraceptive, on request.
Downpatrick said they would only prescribe it to under-18s.
The Mid-Ulster said some of its doctors would prescribe it but others objected on ethical grounds.
The Mater in Belfast is the only hospital exempt from supplying emergency contraception under its charter.
All of the other hospitals refused.
Despite its name, the pill can be taken up to 72 hours after unprotected sex, but it is more effective the sooner it is taken.
The Department of Health's own recommendations say emergency contraception should be "easily available" and "obtainable when an individual requires it".
The morning-after pill is available at pharmacies, but its cost of £24 could deter some, particularly younger women.
Liz Byrne McCullough of the Family Planning Association said it was "an absolute scandal".
"It is a statutory requirement by health providers. It is ludicrous if people are making moral judgements," she added.
Family planning specialist Dr Olga Elder said she could not think of another condition where casualty departments referred patients to another medical provider.
"Logically, since all the patients who want to use this treatment are women, you have to wonder if this is an infringement of their human rights," she added.
However, not all GPs are willing to prescribe it because of their personal beliefs.
Dr Lorraine McDermott, from Crumlin, said she took the view that she was dealing with two patients, the mother and the baby.
"As a doctor, I am dealing with two patients once conception has occurred - I have to think of both the person sitting in front of me and the baby," she said.
"I took the original Hippocratic oath when I qualified, which said that I would not do anything to cause an abortion."
Law lecturer Rosemary Craig said that hospitals could be in breach of their duty of care by refusing the treatment to patients.
The Department of Health said in a statement on Tuesday: "Emergency contraception is widely available through General Practitioners, Family Planning and Young Persons Sexual Health Clinics and some acute hospital A&E Departments.
"It can also be purchased over the counter at any pharmacy."
"As with the prescription of all drugs, the prescription of emergency contraception is a clinical decision taken on a case-by-case basis," the spokesperson added.