The effect of somatostatin on portal pressure is mediated by splanchnic arterial vasoconstriction which induces a reduction in portal blood flow and pressure. One of the most important characteristics of somatostatin is that its splanchnic effect is not accompanied by major systemic hemodynamic effects. Somatostatin has been used in several controlled trials to test its potential in controlling acute variceal bleeding. The results remain controversial. Different findings in existing clinical trials may derive in part from distinct protocols for somatostatin administration. Published trials suggest that somatostatin may be as effective as vasopressin in the acute management of variceal bleeding. However, since the efficacy of vasopressin has been questioned, a comparison of two potentially ineffective drugs cannot establish definitively the efficacy of somatostatin in controlling variceal bleeding. The most significant finding of the two published studies has been the lower incidence of minor and major complications with somatostatin when compared to vasopressin. Newer trials in progress may shed new light into the potential use of somatostatin for the treatment of variceal bleeding.