People with epilepsy in Wales are facing an average wait of eight months or more to see a specialist, compared with six weeks in England.
Epileptic seizures can be controlled by drug therapy
Epilepsy Wales says there are only 14 full-time equivalent neurologists in Wales, rather than the 45 there should be, based on population levels.
The Welsh Assembly Government said it was bringing forward plans to improve services, but not until next year.
One expert said people in England would be taken aback by the delay in Wales.
Phil Smith, consultant neurologist in the Welsh Epilepsy Unit at the University Hospital of Wales, Cardiff, told the BBC's Eye on Wales programme that a drive to get English waiting lists down had been successful.
But he said the situation was "less impressive" in Wales.
"People in England will be surprised to hear that it's above eight months at the moment. Their waiting times are more like six weeks," he said.
"We do prioritise people with a first suspected seizure, we expect to see them hopefully within two weeks, but in practice within four or six weeks because of the pressures on the services."
Mr Smith also felt the public were not very aware of the condition.
"The main thing is that there's no famous public figure who will acknowledge that they have epilepsy," he said.
"Unfortunately, people in the public eye who are in a position to make a difference choose to conceal it, because they recognise that actually coming out and saying they have epilepsy might jeopardise their chances of progression."
Jacqui Bate, chair of Gwent Epilepsy, was diagnosed with the condition 15 years ago.
She said: "I fall to the floor, I become unconscious and convulse, which is where the body tightens the muscles and shakes.
"I'm not totally under control at the moment but I can go quite a few months without having a seizure.
"It's hard to get a job while you're having the seizures because you can't guarantee that you can go into work every day."
According to Epilepsy Wales, between 20,000 and 30,000 people in Wales have the condition.
The charity has been in discussions with the assembly government for new guidelines and practices.
Spokeswoman Lesley Morris said: "It became fairly evident that the money is not there; you cannot suddenly invent 30 neurologists within 5 years.
"Everyone realised that we needed to make a document we can accept and access.
"Instead of giving a wish list that's going to sit on a shelf we're actually going to have a document that is accessible and achievable."
A public consultation on epilepsy service development in Wales will begin in January.