There is considerable controversy as regards the exact cause of bleeding from esophageal varices. This study examined changes in the mucosa of such patients in an effort to understand the underlying mechanisms. Fifty patients were studied, 20 with a history of variceal bleeding and 30 without who served as controls. Endoscopic biopsies were taken from the inter-variceal mucosa within 5 cm from the cardia and were examined histopathologically. The results showed dilated intra-epithelial blood-filled channels within the squamous epithelium and the lamina propria in all bleeders, and in 50% of the non-bleeders. Evidence of esophagitis was also more pronounced in bleeders (50%) than in non-bleeders (23.3%). It is our opinion that esophagitis and the presence of dilated blood-filled channels may play a role in the initiation of variceal bleeding.