Gastrin is a peptide hormone, which acts not only to regulate gastric acid secretion, but also to exert physiological actions such as the regulation of sodium balance. From a case (n = 95)-control (n = 82) study in Fuyang People's Hospital, Anhui Province, China, we found that the fasting serum gastrin levels are similar in normotensive and hypertensive adults but increased to higher levels in the latter group than in the former group after a mixed meal. We suggest that gastrin is involved in the regulation of blood pressure, possibly via the regulation of sodium and water metabolism and/or renin-angiotensin-aldosterone system. However, the mechanism remains to be determined.