People are getting better care despite NHS bed numbers falling by a third in the last 20 years, health managers say.
Bed numbers have been declining since the 1950s
The NHS Confederation, which represents NHS bosses, says it wants to dispel the "myth" that fewer beds mean less care.
In a briefing paper, it said technological advancement and better community care meant patients could spend less time in hospital.
Doctors said while care was improving, some hospitals had cut beds too much and were compromising care.
The paper acknowledges that bed closures caused "emotions to run high". It points out that from 1984 to 2004, the number of beds fell from 211,617 to 145,218 (31%).
In fact, numbers have been falling since the late 1950s - a pattern that has been repeated in countries across Europe for a variety of reasons.
Advances like key-hole surgery mean procedures such as hernia and gall bladder removals can either be carried out as day surgery or require only a few days in surgery, compared to a week or more a few decades ago.
As well as patients needing less recovery time, the nature of care has changed with more being done in the community, such as advanced GP services and greater provision health professionals, such as physiotherapists.
Chemotherapy can now be administered at home, ambulance crews are treating people on site rather than bringing them into hospital and the better management of chronic conditions such as diabetes has kept people out of hospital.
Gill Morgan, chief executive of the NHS Confederation, said: "More patients are being treated faster and more effectively than ever before by the NHS.
"The number of actual beds has steadily reduced, yet the amount of care the service is able to deliver has dramatically increased."
Instead, Ms Morgan said the public should move away from concentrating on bed numbers.
"We need to move away from this fixation with bricks and mortar," she said.
"The world is changing, patients' needs are changing and the NHS is adapting to meet those needs.
"It's not surprising that people believe that more beds mean better patient care - this has been the assumption for many years.
"We must start judging the NHS by the number of people we make better and keep well, not by the amount of beds which are, after all, only hospital furniture.
"Developments in technology and changes in the way treatment is delivered mean we simply need fewer beds."
But Paul Miller, chairman of the British Medical Association's consultants committee, said there were still cases where cost pressures had meant too many beds had been lost.
"Doctors do sometimes struggle to get patients into wards.
"We may have to spread people around the hospital, but that means that patients who need to be on a surgical ward may end up on another type of ward which does not have the right resources. That can compromise patient care.
"The NHS is facing large deficits and this is putting even more pressure on hospitals to make cuts."
Roger Goss, of the group Patient Concern, said the NHS Confederation's view was only "half the truth".
"We have one of the worst MRSA and other hospital acquired infection rates in Europe.
"This is primarily a result of over-use of hospital beds and the lack of spare capacity to isolate infected patients.
"Day surgery is fine provided it is not overdone. The danger of trying to get as many people in and out on the same day is an increase in complications rates and the consequential need to re-admit patients."
Niall Dickson, of the independent healthcare charity the King's Fund, said: "The trick will be to see that as you shut down capacity in the big hospitals that you are able at the same time to get smarter in the way that you deliver community services."