OBJECTIVE: Previous studies on the effects of chiropractic treatment on blood pressure (BP) and pulse rate (PR) have reported decreases in both systolic and diastolic BP, as well as PR. However, many of those studies have been criticized for various study flaws, and accused of drawing erroneous conclusions, due to small sample size and various methodological concerns. The purpose of this randomized controlled trial (RCT) is to measure the effects of specific thoracic (T5 to T1) chiropractic adjustments on BP and PR in a larger sample size of both normotensive and hypertensive humans.