Triage is the process of determining the priority of patients' treatments based on the severity of their condition.
The hospital's Dr Ovia Bue said the new system would help improve the quality of care provided to emergency patients.
"Triage allows us to identify patients who need immediate treatment. The emergency department is now colour-coded, such that the patients requiring resuscitation are taken to the red area. Patients with other care needs may be directed to yellow and green areas. This simple system will help ensure that we can provide the best possible care to the greatest number of patients," Dr Bue said.
"All patients who go to emergency at Gerehu will now be registered and triaged on arrival. Under the new system, emergency doctors will see patients in order of urgency, not time of arrival."
The new system has been developed by the World Health Organisation, Médecins Sans Frontières and the International Committee of the Red Cross, but has been adapted for Papua New Guinea by a team from the Australasian College for Emergency Medicine (ACEM).
ACEM president Dr Simon Judkins said that implementing the new system had been a collaborative project between emergency physicians and nurses from Australia and PNG, "and I am proud that our organisation has been able to support it".
The implementation of the new system is part of an emergency care strengthening project funded by the Australian Government through the PNG-Australia Partnership. With the support of an Australian Government Friendship Grant, the triage system will also be implemented at Mount Hagen Provincial Hospital later this year.
PNG Society of Emergency Medicine Dr Gary Nou said he was very excited to be working in partnership with colleagues and friends from Australia.
"This collaborative project will help us to provide timely and quality care for our patients. It is an exciting day for Gerehu General Hospital."