To study the effects of caffeine on serum lipids and blood pressure, we conducted a double-blind, randomized trial with two parallel groups in 69 young, healthy subjects. After a 3-wk run-in period, subjects were randomly assigned to one of two groups receiving either 4-6 140-mL cups filtered decaffeinated coffee per day and an equal number of pills containing 75 mg caffeine or 4-6 140-mL cups filtered decaffeinated coffee per day and an equal number of placebo pills, for 9 wk. In both groups caffeine intake from other sources was not allowed. The main finding of this study is that abstinence from caffeine for a period of 9 wk has no effect on either serum lipids or blood pressure.