 Peritoneal metastases appear in a great proportion of patients affected by gastric carcinoma. Involved mechanisms are poorly understood though experimentally it has been demonstrated that neoplastic cells exfoliated from primary tumor can only implant and proliferate in areas of damaged peritoneum. Objectives: to study ultra-structure of peritoneal surface by electronic microscopy in control subjects and in patients with early or locally advanced gastric cancer looking for spontaneous changes in peritoneal surface not related with surgical injury. 