The aim of this study was to assess the effect of haemodynamic changes on portal circulation after splenectomy vasoligation and to correlate these changes with the incidence of Portal Vein Thrombosis. The results of the present study shows that there is significant decrease in the diameter of portal vein and increase in the platelet count postsplenectomy vasoligation while there was insignificant changes in velocity, portal flow rate, congestive index & prothrombin concentration. But in relation to incidence of Portal Vein Thrombosis insignificant changes were found haemodynamically. Patients with either fever or abdominal pain should be suspected for portal vein thrombosis after splenectomy. Prophylactic heparin may be given at a higher dose to decrease the incidence of P.V.T. Early treatment is more likely to restore normal flow in the portal vein. Routine Doppler ultrasonography after splenectomy might enable early diagnosis and effective treatment.