We have investigated the financial costs of attempts to optimise blood pressure control in patients referred to our blood pressure clinic. At first referral, the average blood pressure in the 262 patients studied were 167/97 mmHg and the monthly costs of the antihypertensive drugs was 23.44 pounds. After 1 year of clinic attendance, the blood pressure was reduced to 149/87 mmHg, and the average drug costs had risen to 30.68 pounds. For drug expenditure alone, the cost of reducing systolic blood pressure by 1 mmHg was 0.36p pounds (Euro 0.55, USD 0.55) and for diastolic blood pressure the cost-was 0.72p pounds (Euro 1.12, USD 1.13).