Intestinal microflora plays an important role in the etiopathogenesis and course of inflammatory bowel diseases (IBD) – ulcerative colitis (UC) and Crohn’s disease (CD). The composition and function of enteric microflora in patients with IBD reveal substantial changes in comparison with healthy persons. Currently there is no solid evidence to support the role of any specific bacterial causative agent in those diseases. Initial evidence concerning the involvement of Helicobacter species in intestinal inflammation came from animal studies. Several entero-heaptic Helicobacter species have been shown to induce colitis in rodents and primates. In the last few years, members of the Helicobacteriaceae have been detected in a significantly high number in colonic biopsies in patients with IBD, especially with CD, using specific PCR analysis and bacterial culture methods. Entero-hepatic Helicobacter species have also been identified in fecal specimens from children with CD. Simultaneously, many results show a signifi-cantly lower prevalence of H. pylori gastritis in patients with IBD compared to controls. The answer whether Helicobacter species play a role in the actual causality of IBD is still to be determined.