Helicobacter pylori infection sometimes leads to an antigastric autoimmunity that ultimately develops into complete atrophy of the glands of the gastric mucosal glands. It has been found that the "classical" parietal cell antibody positive and H. pylori induced autoimmune gastritis share common aspects of histomorphology, stages, and pathomechanisms. Healing of H. pylori associated active preatrophic autoimmune gastritis by eradication treatment has been confirmed both in case reports and in prospective and retrospective studies. This leads to a general practice-oriented four-step concept for diagnosis and treatment in daily routine: (a) Histological work-up on the basis of: lymphocytic infiltration of the glands of the corpus and fundic mucosa, focal destruction in individual corpus glands, reactive hypertrophy of the parietal cells, and search for H. pylori. (b) Additional serological work-up if histological evidence of H. pylori is lacking: determination of H. pylori and parietal cell antibodies in the serum. (c) Initiation of an established H. pylori eradication therapy if histology and/or serology is positive for H. pylori. (d) Histological and serological follow-up for 9-12 months to monitor the results of treatment.