The records of 79 patients admitted to the hospital from January 1985 through December 1990 for acute esophageal hemorrhage were analyzed to determine the influence of liver disease and/or portal hypertension on the severity of bleeding from Mallory-Weiss syndrome. Forty- two patients had bled from Mallory-Weiss syndrome; 8 had liver disease and nonbleeding esophageal varices, 6 had liver disease without varices, and 28 had no evidence of liver disease. The severity of bleeding was determined by the transfusion requirement for each group. The number of units of blood needed for patients with liver disease was significantly increased (p < 0.005) over the number of units necessary for patients without liver disease. There was no statistically significant difference in the transfusion requirement between liver disease patients with and without varices (i.e., portal hypertension). The transfusion requirement was also unrelated to the Child classification of hepatic functional reserve. We conclude that the severity of bleeding from Mallory-Weiss syndrome is primarily related to the status of liver function and that portal hypertension does not make an additive contribution.