This chapter examines the effects of dietary caffeine on blood pressure and considers the implications of those effects for cardiovascular disease. It focuses on studies of chronic caffeine effects because these are likely to be more directly indicative of the effects of caffeine as ordinarily consumed. It has been shown conclusively that caffeine can elevate blood pressure in the range of 5 to 15 mg Hg systolic and 5 to 10 mg Hg diastolic across a wide age range, with effects lasting for up to several hours in healthy men and women. As part of the much larger body of epidemiological research on caffeine and cardiovascular disease, 18 population studies have been specifically concerned with caffeine and blood pressure. Within the extensive literature concerning caffeine and blood pressure, particular attention has been given to the acute effects of a single dose of the drug.