Helicobacter pylori (HP) eradication therapy do not always achieve eradication. One of the probable reasons for the ineffectiveness of eradication treatment is bacillary-coccoid transformation of HP. We present that in cases when HP eradication was not achieved after the first line eradication therapy, patients usually had had a high degree of gastric mucosa colonization with coccoid forms of HP before the start of H. pylori eradication therapy. So, we confirmed the hypothesis of helicobacter coccoid forms can avoid eradication.