Wide variations in NHS spending may be denying patients fair access to drugs and treatment, a study says.
The King's Fund looked at government data
The King's Fund think tank found that some English trusts spent four times as much on certain diseases than others.
The research, compiled from government data from 2003-4 to 2004-5, also showed mental health got the most cash, followed by heart disease and cancer.
But NHS managers said variations in spending were not always bad and could reflect the burden of disease.
The research by the health think-tank looked at spending by 303 primary care trusts (PCTs), which are responsible for 80% of the NHS budget and fund hospital, GP and community treatment.
It is the first time the information has been presented in this way.
It showed Islington PCT spends £259 per head on mental health each year - four times the £66 spent by Bracknell Forest PCT once deprivation is taken into account.
For cancer there were similar differences. Daventry and South Northamptonshire PCT spent £132 per head on cancer and tumours, while Heart of Birmingham PCT spent about a quarter of that.
Researchers also analysed overall spending on particular disease groups. The greatest proportion - over £7bn - was spent on mental health, with heart disease absorbing nearly £6bn and cancer just over £3.5bn.
The report said there were differences in spending which only appeared to be "partially explained" by need and therefore raised questions over whether spending variations were having "adverse effects on equity and efficiency".
King's Fund chief economist Professor John Appleby said: "The new data is very revealing and raises serious questions about the consistency of decisions PCTs make about how much they spend on different diseases."
Campaigners also criticised the variations in spending.
Sophie Corlett, policy director at the mental health charity Mind, said: "We know that in many areas primary care mental health services are severely lacking."
And Cancer Backup chief executive Joanne Rule said: "What people will want to know after seeing this research is, will I receive good cancer care in my area if I need it?"
But Nigel Edwards, director of policy at the NHS Confederation, said: "Variation in the delivery of health services or the 'postcode lottery' as it's often called is frequently seen as a problem by politicians and the public.
"Yet at the same time they say that they want less central control in health and more decisions to be taken locally - there is a direct trade off between them.
"The healthcare priorities of the people of Brighton will be different to the priorities of those living in Bradford."
Health Minister Lord Warner agreed. "This is not about a postcode lottery because money is allocated to primary care trusts on the basis of health need.
"Some variations in spending across the country are to be expected as people respond to the different needs of local communities."