Of course it goes without saying that prevention is better than cure. That is why, in recent years, there has been a growing body of opinion in favour of putting more resources into health education and (preventive) measures. The argument is that ignorance of, for example, basic (hygiene) or the dangers of an unhealthy diet or lifestyle needs to be combatted by special nationwide publicity (campaigns), as well as longer-term health education. Obviously,there is a strong human argument for catching any medical condition as early as possible. There is also an economic argument for doing so. Statistics demonstrate the cost-effectiveness of treating a condition in the early stages, rather than delaying until more expensive and (prolonged) treatment is necessary. Then there are social or economic costs, perhaps in terms of loss of earnings for the family (concerned) or unemployed benefit paid by the state. So far so good, but the difficulties start when we try to define what the 'proportion' of the budget should be, (particularly) if the funds will be 'diverted from treatment'. Decisions on exactly how much of the total health (budget) should be spent in this way are not a matter for the non-specialist, but should be made on the basis of an accepted health service model. This is the point at which real problems occur - the formulation of the model. How do we (accurately) measure which health education campaigns are effective in both medical and financial terms? How do we agree about the medical efficacy of various screening programmes, for example, when the medical establishment itself does not agree? A very (rigorous) process of evaluation is called for, so that we can make informed decisions.