To investigate the effectiveness and safety of the Sengstaken-Blakemore (SB) tube compared with the Linton-Nachlas (LN) tube, a randomized clinical trial was carried out between both types of balloon. Seventy-nine patients suffering from gastrointestinal bleeding attributed to esophagogastric varices were included in the study. Both types of esophageal tamponade showed great effectiveness in obtaining primary hemostasis (86%), but when the bleeding was from esophageal varices, the SB tube achieved permanent hemostasis more frequently (52%) than did the LN tube (30%). In bleeding gastric varices the SB tube failed in all of the cases, but primary hemostasis was obtained with the LN tube in 50% of them. Better tolerance and greater effectiveness were obtained when the SB tube was applied without external traction. The usefulness of esophageal tamponade for bleeding varices was higher when performed within 6 hr of the onset of hemorrhage.