Management at University Hospital Kerry has urged people to “keep our Emergency Department services for the patients who need them most.”
The appeal was issued because of “significant overcrowding” at the hospital in recent days.
Hospital management contacted local GPs and advised people to only attend the hospital in the case of a genuine emergency.
Where possible, their local GP or out of hours doctors' service should be consulted in the first instance.
“We are asking people to think about all their care and treatment options and keep our ED services for the patients who need them most,” management stated.
If people are seriously injured or ill or worried that their life is at risk healthcare staff at the ED will assess and treat them as a priority.
Staff and management are endeavouring to discharge of patients as soon as possible where appropriate.
Management at the hospital apologised for any inconvenience caused and gave an assurance that all clinical staff are working to manage patient flow within the hospital.
According to the HSE's TrolleyGAR, there were 22 patients in the hospital's ED on Friday, with five waiting more than 24 hours and 11 waiting for more than nine hours. In the afternoon the number of patients in the ED had reduced to 17 with nine waiting for more than nine hours.
Local TD and Fianna Fáil's spokesperson for primary care and community health services, John Brassil, said overcrowding at the Kerry hospital was “completely unacceptable” but not unexpected.
“Despite having raised concerns over many years about capacity issues, management is being forced to ask people to stay away,” said Mr Brassil.
The hospital came under pressure every summer, a time when there was a significant increase in the population of Kerry.
“This is not a new phenomenon and is something I have been raising for years,” said Mr Brassil, who urged Health Minister, Simon Harris, to "wake up" to the seriousness of the issue.
The ED was effectively closed to patients because it did not have the necessary resources to deal with the extra capacity, he said.
“There are also knock-on issues from the lack of home-help packages being approved and the slow rate of Fair Deal packages being approved,” he added.
Nursing Homes Ireland said hospital management must engage with nursing homes and pointed out that 17 private and voluntary nursing homes in Co Kerry had 740 registered beds.