The Welsh Ambulance Service is reminding people not to call 999 unless it is a genuine emergency.
The service says it took 31,219 non-urgent calls in the last 12 months alone.
Of those calls, only 670 required an ambulance, and just three needed a patient to be taken to hospital.
They included a woman who dialled 999 to ask if the green part of a potato was poisonous, and a caller whose daughter had drunk water from a dog's bowl.
The Welsh Ambulance Service says it's working hard to reduce unnecessary hospital admissions, and support care close to patient's homes.
"We don't want to deter anyone from calling 999, but we want them to think twice before they do. Sadly, we still receive a significant number of inappropriate calls that do not require an ambulance response.
"When people misuse the service it means our precious time is being taken away from someone who really does need our help. During peak periods, like the summer, every non-essential call has the potential to delay a response to a serious emergency."
Health Minister, Mark Drakeford has set a target for an '' urgent improvement" in ambulance response times . He's demanding that the Welsh Ambulance Service steps up its performance within three months.
The Welsh Ambulance Service has responded to criticism over its failure to meet its response time targets for the most urgent calls.
It says its response times have been affected by an increase in the number of calls received, and "lengthy handover delays at some hospitals."
The service says it recognises the fact that it does not always meet its targets, but says it is working as hard as possible to provide the best treatment for patients.
The Welsh Ambulance Service took 36,544 calls in May, up by more than 1,350 calls from the previous month and more than 1,700 calls from the same period last year.
The emergency healthcare system across Wales is facing continuous pressure with an ageing population and more people suffering long-term conditions.
An increase in the most serious type of emergency calls combined with lengthy handover delays at some hospitals has had an impact on our response times to incidents, and we would like to recognise the hard work, commitment and dedication of all our staff during this difficult time.
We recognise that on occasion we are short of the eight-minute target for the most serious calls, but are working, and will continue to work, as hard as we can to get to patients as quickly as possible.
We are committed to improving ambulance services in Wales as outlined in our clinical transformation and modernisation programme, Working Together for Success.
– Mike Collins, Director of Service Delivery, Welsh Ambulance Service NHS Trust
It also urges the public to use the most appropriate NHS services, and says "please remember only to dial 999 if someone is seriously ill or injured, or their life is at risk."
Plaid Cymru's Health spokeswoman Elin Jones is calling the latest ambulance service response times "disastrous", after it again failed to meet response targets.
These disastrous figures show that the Labour Welsh Government has once again failed to meet its target. This is the worst performance in over a year and reflects Labour's failure to properly run the health service.
Behind these statistics are real patients who have waited too long for life saving emergency treatment and have had their health suffer as a result.
According to official figures released today, the Welsh Ambulance Service has again failed to meet its response time targets.
In May, 54.1 per cent of ambulances reached life threatening incidents in eight minutes down from 56.7 per cent in April and below the target of 65 per cent.
Ambulance response times for May are very disappointing. There is more health boards can do to help but the Welsh Ambulance Service itself needs to demonstrate urgent improvements in its performance.The key elements of the McClelland review have now been put in place. Welsh Government investment has upgraded the ambulance fleet. In this financial year, an extra £7.5m has been agreed, which will allow the recruitment of more than 100 frontline staff. It is now for the Welsh Ambulance Service to turn all this into the required standard of performance.
– Welsh Government Spokesperson
The Welsh Conservatives are blaming a lack of investment from Labour ministers and a failure to address logjams at A&E departments.
Another month and another fall in ambulance response times in the Labour run Welsh NHS. Labour Ministers have missed their ambulance response time target for critical category A life threatening calls almost every month for the past two years. An immediate medical response to a heart attack, stroke or serious accident can make the difference between life and death.
– Darren Millar AM, Shadow Health Minister
The Leader of the Welsh Liberal Democrats, Kirsty Williams is labelling the figures as a "national disgrace".
Targets aren't being met. Ambulance response times are getting worse. Year after year, month after month, this situation is getting worse but the Welsh Labour Government is still failing to do anything about it.
– Kirsty Williams AM, Leader of the Welsh Liberal Democrats
Responding to today's figures the ambulance service response times which showed targets had been missed again for the most urgent 999 calls, the Welsh Government said:
We are disappointed to note the national response time target was not met. New arrangements for the commissioning of emergency ambulance services came into force on April 1, 2014 and we expect health boards to drive forward improved performance over the coming months
People living in the Bridgend area are being encouraged to take part in the Welsh Ambulance Service's First Responder Scheme.
First Responders are volunteers who give up their spare time to attend appropriate 999 calls and give first hand emergency care to people in their community.
The Trust is especially keen to recruit in Maesteg, Porthcawl, Pyle and Kenfig Hill.
Every second counts when you're trying to save someone's life, and Community First Responder schemes are hugely beneficial in helping the ambulance service provide the best possible pre-hospital care for patients.
Many of our volunteers have taken experiences that life has thrown at them, such as seeing a loved one suffer a heart attack, and have moulded them into a positive outlook to help family, friends and neighbours.
If you are proud of the community in which you live, becoming a first responder can really help the heart of your village or town keeping beating long into the future.
– Stephen Roberts, Regional First Responder Officer