This preliminary study included five patients with a history of haematemesis resulting from rupture of oesophageal varices complicating schistosomal hepatic fibrosis. Simultaneous measurements were taken of the endoscopic variceal pressure (EVP) and the free portal pressure (FPP) obtained by the cannulation of a mesenteric vein radical. These measurements were taken after laparotomy, after removing the spleen and after devascularization of the lower oesophagus and upper two thirds of the stomach. At the beginning the EVP was found to be identical with the FPP. Following splenectomy, the EVP dropped from a mean of 41.9 cm H2O to a mean of 25.8 cm H2O, whereas the FPP dropped from 40.7 cm H2O to 27.8 cm H2O. After decongestion, the EVP had a mean of 21.3 cm H2O and the FPP had a mean of 32 cm H2O. Two weeks after the operation the EVP remained unchanged at the end of the operation in two cases and increased by 5 cm H2O in one case. Accordingly it was concluded that Hassab's operation results in an immediate diminution of the EVP and FPP. However, the long-term results of this operation required further studies.