OBJECTIVE To determine the concentrations of interleukin-1 beta, interleukin-6, and interleukin-8 in tissue homogenates of mucosal biopsy specimens from Helicobacter pylori-positive and -negative patients. METHODS In 43 consecutive patients who underwent upper gastrointestinal endoscopy, seven antral biopsies were taken; three specimens were used for cytokine determination and the remaining four biopsies were processed for H. pylori detection. Peripheral venous blood was collected and IgG to H. pylori was assayed by an ELISA technique. RESULTS Twenty-nine of 43 patients (67%) were histologically positive for H. pylori; all had chronic gastritis. The mucosal levels of interleukin-6 and interleukin-8 were significantly higher in H. pylori-positive patients than in the negative patients (p < 0.001). A significantly higher percentage of interleukin-8 was found in patients colonized by H. pylori with active superficial chronic gastritis (85.7%), compared to quiescent superficial gastritis (12.5%) (p < 0.01), and the median and range were, respectively, 400 (0-1000) and 0 (0-200) pg/mg protein (p < 0.001). In patients with active superficial gastritis, a significant correlation between interleukin-6 and -8 was found (p 0.01). No difference was found regarding the mucosal levels of interleukin-1 beta according to the presence of H. pylori. CONCLUSIONS These results suggest a possible pathogenetic role for interleukin-6 and interleukin-8 in H. pylori-associated gastritis.