The stomach cancer develops on dysplastic lesions of gastric mucosa. It can be found in every precancerous condition, as chronic gastritis, gastric adenoma, giant rugal hypertrophy, chronic peptic ulcer, gastric stump after partial resection, pernicious anaemia. So, this dysplastic change is not a specific lesion. Different classifications are known for grading of gastric dysplasia. Authors evaluated them compared with each other. The signs of dysplasia were studied in 306 gastric aimed biopsy specimens from 233 patients between 1979-1990. In this material severe dysplasia occurred in 20.6%. It means a frequency of 0.84% regarding all gastric endoscopies in the same period of time. The endoscopic investigation revealed a protruded lesion in 18.5% and excavated one in 45.9%. What is very important, local change could not be detected in 35.6%. Follow-up study could be performed in 49 patients in a period of 1-7 years. In this group cancer developed in five patients. By the other hand, 22 gastric carcinomas were proved amongst 233 patients. The authors' recommendation is to follow-up the patients bearing gastric dysplasia at least during 10 years after the diagnosis.