Summary. There is now indisputable evidence from therapeutic trials that pharmacologic treatment in symptomatic and pre‐symptomatic subjects can reduce morbidity and mortality from hypertensive disease. Furthermore, there has been a striking fall in national mortality rates from hypertensive diseases. In Australia rates for cerebrovascular disease were rising slowly in the decade befor the introduction of sympatholytic drugs in about 1950. Since then the rate has fallen dramatically. The reversal in trend and its timing, and a consideration of numbers of patients under treatment and the incremental fall in deaths each year are consistent with such a conclusion.Some 15% of adults in many western communities are hypertensive. In Australia, of 36,000 subjects screened, 16.3% had a diastolic blood pressure of 95 mm or greater on two separate visits, or were on hypotensive therapy. Of these 35% were unaware of the condition and 45% were taking therapy. In 11% of those not on treatment, the diastolic pressure was 110 or systolic pressure was 200 or greater.In 1973 the cost of drugs in Australia specified for hypertension was $A13,000,000. In addition $A6,000,000 was spent on diuretics and $A400,000 on beta antagonist drugs (assuming that 40% of the cost of diuretics and 20% of the cost of beta antagonists were prescribed for hypertensive patients). The total drug bill was $A19,000,000.The fall in national mortality rates above suggest that for this annual drug bill, 2,000 lives are now saved each year. If all hypertensives in Australia were on therapy, many more lives would by saved, for an additional cost of drugs of $A17,000,000. The total drug bill for the nation would be $A44,000,000. Other debits would include medical expenses, costs of a national screening progrmme (approximately 60c.per person) and the side effects of therapy. A major problem for health planners if to cut these costs while maintaining the advantages of therapy. Better knowledge of the features and pattern of progression of hypertension in the community is necessary toj permit this, and some aspects of national and internatonal efforts to acquire this knowledge are described.