Wollongong Hospital recorded an "unseasonal increase" in the number of emergency department patients in the last quarter, with 13,443 people through the doors.
The latest Hospital Quarterly report from the Bureau of Health Information shows that from April to June, 1029 more patients attended the Wollongong ED than in the corresponding period last year.
Bureau of Health Information acting chief executive Kim Browne said the 8 per cent increase was part of a statewide trend.
"The total number of patients attending NSW emergency departments from April to June was 546,000, up 7 per cent on the same quarter last year," she said.
"Usually this is the quietest time of year for emergency departments, so this is an unseasonal increase in patient activity."
Ms Browne said the increase in patients was spread across the more urgent triage categories statewide.
This was evident at Wollongong Hospital, where there was a 23 per cent increase in triage 2 (imminently life-threatening conditions such as chest pain) compared to the same quarter last year.
Meantime, there was a 6 per cent decrease in less urgent, or triage 5, patients.
"This is a trend which we have been noting over the last four quarters - it's an interesting pattern which we will be watching closely," Ms Browne said.
Despite busier emergency departments, the median times patients waited for treatment were similar to the corresponding quarter last year throughout the state's hospitals.
Waiting times at Wollongong stayed constant for triage 2 patients (between 11 and 46 minutes), with slight increases for triage 3, 4 and 5 patients.
However, Wollongong figures remain high compared to other NSW hospitals. For instance 95 per cent of patients with conditions like a sprained ankle or ear ache started treatment within 117 minutes at Sutherland Hospital, compared with 265 minutes at Wollongong.
The figures showed NSW hospitals - including Wollongong - were yet to meet the National Emergency Access Target.
"The target for NSW in 2012 is for 69 per cent of all patients to leave the emergency departments within four hours - the NSW figure this quarter was 58 per cent," Ms Browne said.
Wollongong Hospital was further away from the target - just 41 per cent of patients left the emergency department within four hours.