Background and Introduction Extra-hepatic Portal Vein Obstruction (EHPVO) is a vascular disease characterized by post-thrombotic obstruction and cavernomatous transformation of portal vein leading to portal hypertension.Aims and objectives To analyze the spectrum of hematological abnormalities in all patients of ‘idiopathic EHPVO’ referred to Hematology department.Methods It is a retrospective study in which files of all patients of EHPVO presenting to hematology department over a period of 22 months were retrieved. All cases of chronic liver disease, malignancy and post-surgery were excluded. The laboratory evaluation included ELISA for anti-beta-2-glycoprotein1 antibodies, anti-cardiolipin antibodies, Protein C, Protein S, Antithrombin-III and plasma homocysteine, screening for Activated Protein C-resistance, mutation analysis for Factor V Leiden, MTHFR, JAK2 V617F, prothrombin G20210A mutation and flow cytometry for paroxysmal nocturnal hemoglobinuria (PNH) clone.Results Out of 122 patients, 52.4% (64) had underlying hematological cause for EHPVO. Hyperhomocysteinemia (15.5%) was the most common hematological abnormality followed by JAK2V617F allele positivity (10.6%) and antiphospholipid antibody (APLA) (10.6%). After excluding hyperhomocysteinemia, Protein C deficiency was the commonest cause in younger age group (<25yrs) while latent Myeloproliferative neoplasm (MPN) was commonest in the older subset. 4 patients in the older group had high PNH clone size on granulocytes and monocytes. In our study, the overall prevalence of acquired causes of EHPVO (hyperhomocysteinemia and positivity for JAK2V617F allele) was more common than inherited causes.Conclusion All patients with idiopathic EHPVO should undergo comprehensive evaluation for underlying hematological abnormalities especially for latent myeloproliferative neoplasm.