The median time spent in John Hunter Hospital's emergency department from treatment to discharge was five hours and 24 minutes from January to March.
The result, which was a record high, has raised questions about the effectiveness of state and federal efforts to take pressure off emergency departments.
Bureau of Health Information data, released on Wednesday, showed one in 10 patients waited 11 hours and 26 minutes at John Hunter over the quarter. This was the worst result on record.
Australian Medical Association NSW president Fred Betros said the "system and level of resources are not fit for purpose".
"The decline is progressive. It's not reversing," Dr Betros said.
"That decline has been reproduced quarter by quarter."
A decade ago, the median time spent in John Hunter's emergency department from treatment to discharge was only two hours and 48 minutes in the January to March quarter.
One in 10 patients waited five hours and 24 minutes at John Hunter's emergency department over the same quarter in 2016.
Dr Betros said there were "small areas of improvement" that the government highlighted each quarter.
"But that isn't enough to say the health system has been fixed," he said.
"The reality is the resourcing in the public hospital system is nowhere near where it should be.
"Every aspect of hospital care - elective, emergency, diagnostic, outpatient care - is under incredible pressure."
The federal government has established urgent care clinics in Charlestown, Cessnock and Maitland.
The NSW government has a Healthdirect line for 24-hour advice and an urgent care telehealth service.
Dr Betros said this "hasn't translated into a tangible decrease" in wait times.
NSW Health Minister Ryan Park said 1300 patients were stuck in NSW hospitals each day.
"They are unable to leave our hospitals because they are waiting for Commonwealth aged care or NDIS placement," Mr Park said.
Despite this, Mr Park said the government was "pursuing its own plan to address bed block".
"We are continuing to see progress in emergency department and surgery wait times," he said.
Dr Betros said the AMA supported efforts to "get people out of hospital who should be in nursing home beds".
"That's part of the problem, but it's not all of the problem," he said.
"We have 92,000 people still on the waitlist for elective surgery in NSW. That gives you an idea of the scale of the problem."
In the Hunter New England Health district, 12,380 patients were on waiting lists for surgery in March, a fall from 12,925 at that time last year.
In March 2016, this figure was 8800.
Across the district, the median time spent in the emergency department from treatment to discharge was three hours and 23 minutes from January to March.
This was a record high, as was the one in 10 patients waiting a median of nine hours and 11 minutes from treatment to discharge across the district.
Hunter New England Health director of clinical operations Susan Heyman said the district recorded 112,920 emergency department attendances from January to March.
This was a 0.8 per cent rise on the same quarter last year.
"Despite increasing demand, performance improved in key areas, including the number of patients starting treatment on time (68.2 per cent)," Ms Heyman said.
"Even under this pressure, our staff continue to deliver safe, high-quality care to patients."
