Soluble triggering receptor expressed on myeloid cells (sTREM-1) is a novel mediator involved in the pathogenesis of peptic ulcer disease. To investigate the potential role of sTREM-1 in the anti-inflammatory response in chronic gastritis, sTREM-1 was compared with other anti-inflammatory mediators of gastritis. Forty patients with dyspepsia were enrolled: 20 with peptic ulcer and 20 controls without any macroscopic abnormalities. All patients were examined by endoscopy; gastric juice was aspirated and biopsy specimens were collected from the antrum and corpus of the stomach. sTREM-1, interleukin (IL)-8, and IL-10 were estimated by enzyme immunoassays. Median sTREM-1 in patient controls and in patients with peptic ulcer disease was 3.91 and 44.27 pg/ml, respectively (P=0.006). Respective values of IL-8 were 1856.97 and 2030.66 pg/ml (P=0.023); those of IL-10 were 16.92 and 18.43 pg/ml (NS). The odds ratio for the presence of peptic ulcer in the event of a concentration of sTREM-1 higher than 15 pg/ml was 23.22 (95% CI, 2.58-208.62; P=0.002). A positive correlation was found between the ratios of IL-8/sTREM-1 and IL-8/IL-10 (r (s), + 0.365; P=0.021). In conclusion, sTREM-1 is an independent factor for the generation of peptic ulcer disease and might behave as an anti-inflammatory mediator in chronic gastritis.