If you want the best treatment from your GP, make sure you look a million dollars, UK researchers suggest.
The findings were based on 30 GPs
A study found GPs perceived affluent patients as more attractive than patients from deprived backgrounds.
The authors of the study, in a Royal Society of Medicine journal, say this could be one reason why richer patients tend to receive better care.
But GP leaders say it is important "not to jump to conclusions" and that GPs strive to provide an equitable service.
Dr Dermot O'Reilly and colleagues at Queen's University in Belfast took photos of 300 affluent and disadvantaged patients from 15 GP surgeries in Northern Ireland.
The photos were then examined by 30 GPs from practices other than those used by the patients.
Based on the images alone, GPs rated patients from higher socio-economic backgrounds as being more attractive than their poorer peers.
Younger patients were also rated as more attractive than older patients.
The average difference in measures of attractiveness between affluent and deprived patients was the equivalent of 30 years - the difference between someone aged 30 and someone aged 60.
The difference was also more pronounced among the GPs working in the most socio-economically deprived areas.
Dr O'Reilly said: "We know that patients from lower socio-economic groups tend to have shorter consultations, receive less information, are less likely to get a prescription or to be referred to specialist care than the more affluent.
"While it is unfortunate that we judge people on their appearance, the psychology literature shows that humans are conditioned to do so.
"Our study has found that this also occurs during the patient/doctor encounter."
He said GPs and health workers should be aware of this potential bias and try to offset it to ensure that deprived patients are not inadvertently further disadvantaged.
Professor Mayur Lakhani, chairman of the Royal College of General Practitioners, said: "We must not jump to conclusions.
"I want to reassure the public that GPs take seriously their duty to provide patients with high quality care irrespective of their background. Good general practice has an important role in helping the disadvantaged."
But he added: "We must, however, remain vigilant about the issue to ensure that the NHS does everything possible to reduce health inequalities."