Doctors have an ethical duty to prevent waste in the NHS, argues a report by the Academy of Medical Royal Colleges.
Its authors point to potential savings of nearly £2bn. Examples include better use of medication, tests, hospital beds and operating theatres.
The British Medical Association said doctors were ideally placed to identify savings, but patients must come first.
The health secretary said he was determined to tackle avoidable waste in healthcare.
The report is based on the premise that one doctor's waste is another patient's delay, and may even mean treatment is withheld.
The authors argue it is better to develop a culture of finding the best way to do something, and then do it right across the health service.
There are 16 examples of changes to clinical practice which have saved money and benefited patients.
They include medication reviews to prevent adverse drug reactions, which account for 6% of all hospital admissions. The report says eradicating this problem would save £466m.
It also suggests more than £200m could be saved by stopping unnecessary scans.
Other recommendations include:
- Prescribing lower-cost statins, which could save £85m
- Reducing unnecessary face-to-face contact between patients and healthcare professionals by using technology such as e-mail and Skype
- Cutting the number of X-rays for lumbar spine or knee problems, which could save £221m
- More frequent consultant ward visits to ensure patients can be discharged promptly
The report does not provide a definitive total of potential savings, but indicates what a change in culture - where doctors resolve to eradicate waste - could potentially deliver.
Savings in surgery
Surgeons at the Royal Throat Nose and Ear Hospital in London have reduced the number of instruments required for cochlear implant operations, from 96 to 28.
This has saved money on cleaning and wear and tear. And it has reduced the risk of cancellations or costly delays caused by incomplete equipment.
A surgeon at the hospital, Jeremy Lavey, said doctors were well-placed to identify savings.
"We have a responsibility because we're in the best position to say I can use this one, I don't need to use that.
"A manager can't make that decision whereas we are ideally positioned and we have a responsibility to make sure we do that properly," he said.
Professor Terence Stephenson, chairman of the Academy of Medical Royal Colleges, said: "Maintaining NHS services in the future depends on doctors ensuring the best use of resources today.
"Quality of care is a doctor's prime concern. But delivering quality care and promoting value are really two sides of the same coin," he said.
Speaking to BBC Radio 5 live, co-leader of the National Health Action Party Clive Peedell welcomed some of the recommendations, but noted that "a lot of this is already being done" and warned that efficiency savings had already "created real problems".
Areas of potential savings
Professor Sir Bruce Keogh, the NHS England Medical Director, welcomed the report.
"We need to be innovative to tackle the huge financial challenges we are facing, but there are also some more everyday changes that we can make to improve efficiency. This report neatly embodies some practical ideas for more efficient practice," he said.
Health Secretary Jeremy Hunt said: "We have launched a safety campaign aiming to halve avoidable harm and recently published a report showing the costs of unsafe care may be as high as £2.5 billion a year.
"Today's report builds on this and underlines the potential for savings."
Dr Ian Wilson from the British Medical Association said doctors had already played a leading role in helping to find more efficient ways of delivering patient care.
He added a note of caution: "While staff and management should work closely to maximize the use of the NHS's very limited resources, a doctor's primary duty is to their patient, and it is vitally important that decisions around patient care are around clinical value."