Patients in 36 hospital wards across England would not recommend them to their family or friends, according to the results of a new test.
The first results of a survey designed to expose poor patient care revealed the large majority were happy with their treatment.
But some 36 of 4,500 wards were given an overall negative figure in June. This was down from 66 in April.
Despite months of criticism, only one A&E department - Chase Farm Hospital in north London - was given a negative score.
And even then, 295 of 516 patients asked about the hospital said they were "extremely likely" to recommend it and another 167 said they were "likely" to do so.
Overall, A&E services scored between 100 to minus 13 and scores for inpatients ranked from 100 to 43.
But there will be disappointment at the response rate, which was just 13.1% across England.
The so-called Friends and Family Test was announced in January and first introduced in April.
Patients are asked one simple question - whether they are likely to recommend the ward or A&E department they were treated in to friends and family.
They chose from six responses ranging from extremely likely to extremely unlikely and were asked to give reasons for their decision.
A score was created for each hospital by subtracting the number of negative responses from the number of positive ones.
More than 400,000 people completed the survey and results relate to around 4,500 NHS wards and 144 A&E services.
NHS England's national director for patients and information Tim Kelsey said the initiative was a "major step forward".
"Direct patient and citizen feedback is vital to improving the services the NHS provides. Trusts can concentrate their focus on improvement with this information," he said.
"From this first publication, we can see a significant and real variation in the quality of customer service across the NHS.
"There are home truths here and everyone will expect those Trusts who have large numbers of their patients choosing not to recommend their services to respond as quickly as possible."
David Cameron, who is on holiday in Portugal, said: "I want the NHS to put patient satisfaction at the heart of what they do and expect action to be taken at hospitals where patients and staff say standards are not good enough."
Health Secretary Jeremy Hunt called it a "historic moment".
"By making these ratings public, we're giving patients the power to choose the best place for their care - and driving other hospitals to raise their game," he said.
However, critics claimed the data had little meaning because it is not specific enough and is not an accurate way to measure hospital performance.
The new patient charity Point of Care Foundation noted that it is currently impossible to tell whether someone's negative response was due to poor care or an issue such as car parking.
Director Jocelyn Cornwell said: "Some hospitals were using much better methods of collecting feedback but they have had to abandon what they were doing and replace it with this rather blunt instrument which is not good for patients, or for developing useful information to improve health services.
"We would ask the Government to think again about how more useful information on patient care could be collected and used to improve services."
NHS England is to publish monthly updates on patient feedback.
By the end of next year, it hopes to roll the test out to include GP practices, community services and mental health services. All other services will be included by April 2015.