There has been an increase in the number of people being treated within the clinically recommended time frame at emergency departments in NSW public hospitals.

A milder flu season this winter meant fewer people presented themselves to emergency departments across NSW public hospitals, new data shows.

More than 717,700 people presented themselves to emergency departments between July and September, which is a 3.2 per cent decrease from the same period last year, the Bureau of Health Information's latest quarterly data reveals.

BHI chief executive Diane Watson says last year's severe flu season saw more patients at emergency departments compared with this year's milder flu season.

The report, published on Wednesday, found almost three-quarters (73.4 per cent) of patients were treated within clinically recommended time frames which is 2.9 per cent higher than the same period last year.

"While we need to take this year's milder flu season into consideration when looking at these results, it is still encouraging to see results at NSW level have improved compared with the same quarter last year," Dr Watson said in a statement.

While the report shows many hospitals have improved their timeliness of care in emergency departments, there are still improvements to be made, Dr Watson added.