Wait times in emergency rooms in NSW hospitals has remained stable at about four hours or less, according to a new report.

NSW public hospitals have maintained waiting times despite an increase in patients visiting the emergency department, a report shows.

The Bureau of Health Information's report, released on Thursday, says hospitals have increased their services, with a jump in 17,000 patients at emergency departments during January to March 2015 compared to the same quarter last year.

About 75 per cent of patients left emergency departments within four hours in a result that did not change since last year's report.

About 9000 more patients had been admitted to hospital and 374 more elective surgeries were performed across the state.

However, those wanting a hip replacement had to wait longer for the procedure, with the median waiting time increasing by 64 days to a total 238 days.

Non-urgent surgery wait times also increased by five days.