Achlorhydria, determined by the augmented histamine test, is the functional expression of the most severe atrophic gastritis and is followed by a 4- to 6-fold increased risk of gastric cancer, as we found 5 cancers in 114 patients after a mean observation period of 8.4 years. The cancers developed from 1 to 17 years after achlorhydria diagnosis--three cases after more than 9 years. The study showed no difference in gastric cancer risk between patients with and without pernicious anaemia. Spontaneous achlorhydria is the late result of atrophic gastritis, which should be regarded the premalignant condition. The development of gastric cancer from pharmacologically reduced acid secretion must be regarded as highly hypothetical, since this is not followed by atrophic gastritis.