Since the fate and significance of gastric mucosal dysplasia is still largely unknown we have started a follow-up study for patients with dysplasia in the years 1986 and 1987. In this paper the short term results are reported. Dysplasia grade II was found in 2% of all patients and dysplasia grade III in 0.5%. The following results suggest a close-possibly sequential relationship of dysplasia and gastric cancer: dysplasia and gastric cancer are preferentially located in distal parts of the stomach; sex distribution of dysplasia and gastric cancer (especially intestinal type) are similar; considering the mean age of patients with dysplasia or gastric cancer we have observed that patients with dysplasia II were younger than patients with dysplasia III and both were younger than patients with gastric cancer of the intestinal type; during the short term follow-up (12-24 months) 4-8% of patients with dysplasia II and 18-20% of patients with dysplasia III showed a progression; of 26 carcinomas detected by follow-up of patients with dysplasia III 10 were early gastric cancer, 11 resectable with curative intent, 2 were metastatic and 3 without sufficient information for staging. We conclude therefore that gastric dysplasia is probably a true precancerous lesion that helps to identify high risk patients and thus contributes to the objective of an early diagnosis of gastric cancer.