Some research has suggested that decaf coffee may raise blood pressure, but it is not clear if this effect is significant. A small study in young adults found that those who consumed decaf coffee had higher blood pressure than those who drank regular coffee (1). However, it is not clear if this difference is meaningful. Another study found no difference in blood pressure between people who drank decaf and regular coffee (2). So far, the research on whether decaf raises blood pressure is inconclusive. More research is needed to determine if there is a significant effect. If you're concerned about your blood pressure, talk to your doctor about whether you should limit your caffeine intake.