To investigate whether Sengstaken-Blakemore tube tamponade is needed before emergency sclerotherapy, 60 patients with active esophageal variceal bleeding were randomized to receive either immediate injection sclerotherapy (group A) or sclerotherapy preceded by balloon tamponade (group B). Three patients in group A (10%) were completely inaccessible to sclerotherapy. Initial success in stopping bleeding at 24 hours after sclerotherapy was 76% in group A and 81% in group B (p = 0.89). Re-bleeding rate was 27% in group A versus 50% in group B (p = 0.11). Blood requirement was significantly less in group A (3.7 +/- 2.5 units vs. 6.2 +/- 3.2 units, p less than 0.01). Major complications were also significantly less frequently encountered in group A than in group B (14% vs. 39%, p less than 0.05). In-hospital mortality was 24% in group A and 42% in group B (p = 0.14). We conclude that the efficacy of immediate sclerotherapy is comparable to that of delayed sclerotherapy preceded by balloon tamponade. Additionally, significantly less blood requirement and fewer complications were noted in the immediate sclerotherapy group. Thus, emergency sclerotherapy without prior balloon tamponade is feasible and recommended in most patients with acute esophageal variceal hemorrhage.