Studies on the usefulness of blood pressure as a prognostic factor in cardiovascular disease have more often involved investigations of the levels of diastolic or systolic blood pressure. However, blood pressure may be divided into two other components: steady (mean pressure) and pulsatile (pulse pressure). In this study, the relationship of pulse pressure to cardiovascular mortality was investigated in 19 083 men 40 to 69 years old who were undergoing a routine systematic health examination and were being followed up after a mean period of 19.5 years. Subjects were divided into four groups according to age (40 to 54 and 55 to 69 years) and mean arterial pressure (<107 and > or =107 mm Hg). Each group was further divided into four subgroups according to the pulse pressure level. A wide pulse pressure (evaluated according to the quartile group or as a continuous quantitative variable) was an independent and significant predictor of all-cause, total cardiovascular, and, especially, coronary mortality in all age and mean pressure groups. No significant association between pulse pressure and cerebrovascular mortality was observed. In conclusion, in a large population of men with a relatively low cardiovascular risk, a wide pulse pressure is a significant independent predictor of all-cause, cardiovascular, and, especially, coronary mortality.