Gastric cancer is a rather common disease worldwide. In Italy it still accounts for 15,000 deaths annually. A sharp drop in the incidence rate of Lauren's intestinal histotype has been reported, whereas the frequency of the diffuse histotype is relatively steady. If the histogenesis of the latter is still somewhat obscure, the intestinal type confirms the sequence: atrophic gastritis--intestinal metaplasia--dysplasia--neoplasia. These different stages of development can nowadays be singled out through a series of indicators, the most reliable of which are the pepsinogen I/pepsinogen II ratio, the presence of sulphomucins and Lewis antigens in the gastric juices and NOR (Nucleolar Organizer Regions), cell ploidy and oncogenes determination. The genes involved in the neoplastic transformation are mostly oncosuppressors, the most frequent alterations being those relative to the APC gene, p53 and c-myc. In addition to the by now indispensable pathological staging of the disease, the modern prognostic factors are arising great interest: the most significant are the immunohistochemical examination of the peritoneal washing, and cell ploidy. Surgery is still the only potentially curative treatment: the earlier surgery is performed in the course of disease, the greatest the curative potential. The Authors' experience, which includes 400 operated cases with complete follow-up records, is here reported. The resectability rate turned out to be 84%, overall operative mortality was 6.5% with that due to surgical causes along being 3.7%. Overall survival at 5 years was 36%, while that of the curative operations 47%. Good results were obtained with the association surgery + intraoperative radiotherapy which resulted in a significant decrease in local recurrences of the disease.