Assessment of absolute cardiovascular risk is a rational method of managing hypertension. General practitioners and practice nurses were asked to estimate absolute risk in a group of elderly hypertensive patients during clinical practice. Risk was correctly estimated in 21% of patients, underestimated in 63% of patients, and overestimated in 16% of patients. Unless primary health care professionals use cardiovascular risk charts or tables, treatment decisions in primary care may not be made against realistic estimates of patients' susceptibility to cardiovascular disease.