Most people think the NHS should provide treatments "no matter what the cost", according to the results of an opinion poll.
Just over a third said all drugs and treatments should be available, with another 40% believing budgets should be no object to those proved most effective.
The findings - by Ipsos Mori - sparked a call from a left-of-centre think-tank for the public to be better educated by Government on the limits to spending by the health service.
The survey comes in the wake of controversy over a block on the use of highly-expensive breast cancer drug, Herceptin.
Nurse Barbara Clark, from Somerset, threatened to take her case for the drug to the High Court, leading to its eventual approval for use on the NHS by the the National Institute for Health and Clinical Excellence (Nice).
Health campaigners say a whole raft of other ground-breaking drugs are being denied to patients because they are too expensive.
But the Institute for Public Policy Research (IPPR), which commissioned the survey, said ministers needed to explain to patients why the health service had to work within its means.
Only 28% of those polled said "value for money" should be a factor - with those on lower incomes less likely to recognise such a need, the study showed.
The IPPR said that public education, not privatisation or private insurance, was the key to ensuring expectations met the reality of state provision.
Richard Brooks, IPPR associate director, said: "We should all have high expectations of the NHS, but we need to recognise its limits as well. The public needs to understand that value for money means doesn't just mean efficiency - it means hard decisions over drugs and treatments too."
