Fasting serum gastrin was determined in 35 Chinese patients with various types of chronic gastritis and in 23 Chinese control subjects. The mean (.+-. SD) fasting serum gastrin levels for 13 patients with chronic atrophic gastritis, 16 patients with chronic gastritis and 6 patients with acute-on-chronic gastritis were 32.1 (.+-. 38.9) pg/ml, 36.1 (.+-. 23.2) pg/ml and 33.7 (.+-. 19.4) pg/ml, respectively. The mean (.+-. SD) fasting serum gastrin levels for the whole gastritis group (35 patients) and the control group were 34.2 (.+-. 28.8) pg/ml and 24.6 (.+-. 13.7) pg/ml, respectively. Statistical analysis showed that the mean basal serum gastrin levels of the 3 gastritis groups did not differ significantly from control subjects and with each other.