Over 80% of doctors have seen colleagues make mistakes or had concerns about the care being provided, a survey suggests.
The airline industry's reporting system could be used as a model
But Doctors.net.uk found only 15% of incidents which could have led to death or disability were reported.
The National Patient Safety Agency is rolling out an anonymous reporting system across the NHS this year.
But the majority of the 2,500 doctors surveyed backed an independent internet site to log such errors.
Of those questioned, 81% said they did not trust their NHS Trust or the Department of Health to a run a blame-free system for reporting their mistakes.
Dr Neil Bacon, founder of Doctors.net.uk, said: "Existing systems are not trusted by doctors.
"It's meant to be confidential but the culture of no blame isn't a reality in the NHS. It's used as a witch-hunt.
"At the moment we have no way of learning as doctors from each other. Effectively, we are all working in the dark."
Dr Bacon said the only way forward was an anonymous system like those used by airline pilots.
This could be a confidential system on the Internet, he said.
"Doctors want this to change. It isn't doctors being secretive," said Dr Bacon.
He said errors reported ranged from small, day in day out mistakes in prescribing and diagnosing to rare but much more serious mistakes.
"Doctors across the UK have shown a remarkable honesty and frankness about the scale of the problem and a demand that things change for the benefit of their patients," he said.
Time for change
Sue Osborn, Joint Chief Executive of the National Patient Safety Agency which is introducing the NHS's reporting system said: "If we want to maximise the numbers of reports we receive and the amount we learn, we need the trust of clinicians.
"This is why we have developed an anonymous system that will respect the confidentiality of those who take the time to report to us," he said.
Michael Wilks, chairman of the British Medical Association's Medico-Legal Committee, said: "The BMA would welcome a system of reporting that allows clinical mistakes to be openly discussed and analysed.
He said: "Many medical mistakes are a result of system errors rather than the negligence of an individual doctor and so any system that helps prevent medical mistakes, by helping doctors come forward without the fear of being blamed, would hold real benefits for the NHS.
"E-learning systems that allows for reporting medical mistakes should be introduced as part of the planned reform of the clinical negligence system if it is to effectively tackle the blame culture within the NHS," he said.
Mr James Johnson, chairman of the British Medical Association, said: "Doctors are human and therefore inevitably they will sometimes make mistakes. It is vitally important we learn from these mistakes.
"If you can find out why something has gone wrong and share that information you can stop it happening again. But others can best learn from your mistakes if you have a no blame culture.
"There is already a system in place for sharing information about medical errors and
near-misses - it's called the National Patient Safety Agency.
"People can report incidents to the Agency on an anonymous basis if they want to, or can give fuller details. The important thing is to alert everyone to a problem area so that patients are safeguarded in future," he said.
The Royal College of Nursing released new guidelines last week aimed at cutting blood transfusion errors.
It sets out practical step-by-step advice for nurses involved in the transfusion process.
Figures from the Serious Hazards of Transfusion reporting scheme show a 47% increase in reporting of adverse events and near misses since 1996.