Denim has no place on hospital wards or in the GP surgery, say doctors.
Most doctors think denim should be saved for the weekend
Fewer than one in six think it is appropriate for doctors to wear jeans - though some said "smart" denim was permissible.
And three quarters of those surveyed by the British Medical Association's BMA News magazine say they still dress formally for work.
The majority of doctors think how they dress affects how patients view their competence.
The stereotypical doctor in white coat, or consultant in a bow tie may be less evident than they once were.
But many doctors still think certain sartorial standards should be upheld.
Helene Brandon, an obstetrics and gynaecology consultant from Gateshead, said: "We're professionals, for heaven's sake. It's hardly professional to slob about the ward in jeans."
Nottingham consultant thoracic surgeon David Beggs said: "I do not favour the 'dressing down to make the patients feel at home' approach in any way.
"Overall, clean and smart or smart-casual should be the dress code.
"I do think our dress indicates our attitude if not our level of competence and I am sure patients appreciate this."
'Torn and faded' rejected
But Dr William Notcutt, a Norfolk-based consultant anaesthetist who admits to wearing sandals to work, said: "As I look back over my career, I reflect that the consultants with the worst bedside manners were almost exclusively of the sartorially elegant variety."
Dr Notcutt believes his more "unconventional" dress has helped to generate a more relaxed, informal atmosphere which benefited the patient.
Even among those who do wear jeans say they will not just select any old shade of denim.
Lesley Bacon, a London consultant in family planning and reproductive healthcare, said: "Black, reasonably smart ones enable me to carry a mobile.
"Torn and faded ones would be another story."
But she added: "I doubt if a young girl with an unplanned pregnancy and chlamydia notices anything except whether I am kind and reasonably competent."
What patients think does appear to differ depending on their age.
A study carried out in Australia in 2002 found a minimum of two items of formal attire - from a list of dress trousers, dress shirt, tie and white coat - were required to inspire a reasonable level of confidence in a doctor.
And a study carried out in Scotland in the early 1990s found male GPs wearing a suit and tie and female doctors wearing a white coat who were most favoured, especially among older and richer patients.
But some think the whole problem could be solved if doctors wore a standard uniform.
Dr Denzil Edwards, a psychiatrist in Kent, said: "What happened to white coats? They act as a confidence-inspiring, professional identifier, while being social-class neutral, and they protect patients from cross infection."
Durham consultant anaesthetist David Wood added: "'If you spend a lot of time consulting from the end of the bed, or from behind a desk, then a suit is essential.
"If, on the other hand, you actually get close to patients and their evil humours, then a set of "blues" along the lines of ER is appropriate.
"My trust won't pay the bill to have vomit (someone else's of course) cleaned off a suit."
However, some have their own, very individual, dress codes.
One Derbyshire GP described a colleague who wears a fisherman's gilet with dozens of pockets to store his equipment, instead of carrying a case.