A website has been set up by a watchdog to allow patients to see how private and voluntary hospitals and health providers are performing.
Some NHS patients are treated in the private sector
The Healthcare Commission service allows people to run postcode searches for private centres to see how they are doing in meeting 32 core standards.
Data showed hospitals were doing well but one-in-five mental health units were not meeting at least five targets.
The standards cover everything from infection control to staff training.
The data is drawn from the commission's annual State of Healthcare Report, published in October.
MENTAL HEALTH UNITS WITH MOST NOT MET STANDARDS
Crown Lodge Accrington (North) - 15
Chadwick Lodge (South west) - 13
Delph Park Specialist Care Centre (North) - 12
The Willows Independent Hospital (North) - 12
The Churchill Gisburne Clinic (North) - 12
The standards are not the same as those that apply to the NHS but cover broadly similar issues.
October's report revealed that about 50% of independent providers met all 32 minimum standards, but one in 10 failed five or more, broadly similar to NHS organisations.
Of the 176 mental health units, 80% of whose patients are paid for by the NHS, 17% did not meet five or more standards, while 18% met at least 29 and 3% all 32.
A third of the 249 acute hospitals inspected met at least 29 standards with 65 meeting all of them. Just 6% did not meet at least five.
Acute private hospitals perform mainly non-emergency operations, including one in 10 NHS ones.
Of 21 independent sector treatment centres, private clinics which perform minor surgery for the NHS, 11 were inspected.
The watchdog said while compliance was generally good there was also room for improvement.
The commission, which has been inspecting independent providers since 2004, has the power to prosecute or cancel a providers' registration if they do not meet the standards.
Commission chief executive, Anna Walker said: "We want to make sure that patients have access to information about the standards of care they can expect to receive, wherever they receive it.
HOSPITALS WITH MOST NOT MET STANDARDS
Wistons (South east) - 11
Hurlingham Clinic and Spa (South east) - 11
The Hospital Medical Group (Central) - 11
Whelby House (Central) - 10
Bupa Hospital Southampton (South west) - 8
"It's important that patients know that healthcare services meet these standards.
"All healthcare providers should be accountable to the communities they serve."
A spokeswoman for the Patients Association said: "It is good that patients are being given information and that it is being made easily accessible.
"With increasing choice, patients need to know the places they are using are performing well."
A spokeswoman for Rethink, a mental health charity, added: "If mental health units aren't performing well then it is important that this information is in the public domain so that we can try and make a difference to people experiencing mental illness.
"Service users and carers have been telling Rethink for many years about poor standards of care in mental health units and so it's good to have an authoritative voice such as the Healthcare Commission reinforcing this."
Marjorie Wallace, chief executive of the mental health charity Sane, said: "Although it is good in principle that people should be given information and choice, as we know the bleak reality is that the majority of mental health patients have no choice to get care and treatment in tolerable surroundings."
Professor Chris Thompson, director of healthcare services for the Priory Group, which runs Chadwick Lodge, said: "Chadwick Lodge received an inspection report from the Healthcare Commission in February 2006 which raised a number of issues.
"The Priory Group immediately put a wide ranging programme in place to rectify these issues.
"Since that time we are very pleased that clinical standards and patient satisfaction have risen substantially."