Gastritis may be defined as an inflammation of the stomach. The present tendency is to limit the use of the term to those inflammatory conditions which are usually chronic in nature and are characterized by a cellular infiltration and by degenerative or regenerative changes in the surface epithelium, the glands, and the crypts. The purpose of this paper is to present the gross and microscopic features of chronic gastritis. A simple classification of the disease will be followed which, the authors believe, satisfies the needs of the clinician as well as of the pathologist. A review of the literature on the pathology of gastritis reveals the difficulties which faced the early observers. Stomach specimens were rarely obtained for study before postmortem changes had taken place. Injection of the stomach with a tissue fixative as soon as possible after death eliminated much of this difficulty. With the advent of gastrectomy as a surgical procedure, the pathologist was provided with a specimen which represented...