OBJECTIVE Since, contradictory data have been reported about the effect of diverse variants of H. pylori virulence factors on IL-8 induction, we aimed to analyze the effect of this diversity on levels of IL-8 secretion in AGS cell line. BACKGROUND Helicobacter pylori colonizes the human stomach and induces the activation of inflammatory cytokines, including interleukin (IL)-8, in the gastric mucosa. This induction promotes neutrophil and monocyte recruitment that causes gastric tissue damage. METHODS To determine whether different strains of H. pylori and their CagA variants have possible roles on IL-8 induction, polarized AGS cell line was infected with CagA+ H. pylori strains carrying different EPIYA motifs (ABCCC and ABC) and CagA- strain for 24 hours. Difference in stimulation of IL-8 was measured by ELISA. RESULTS IL-8 secretion was elevated in the treated cells with CagA encoding strains compared with the negative one. Furthermore, a noticeably increased level of IL-8 induction was measured by the CagA-EPIYA type ABCCC encoding strain in compare to that carried EPIYA type ABC. CONCLUSIONS Results of this study provide new evidence about different effects of H. pylori strains and possible roles of their CagA variants on IL-8 induction. It seems that not only carriage of cagA and its expression, but also diversity in EPIYA motif be involved in IL-8 induction in the gastric epithelial cells.