Objective: To find an accurate cut-off value for Portal vein diameter as a diagnostic tool for Portal hypertension on comparing with Doppler ultrasound, CT abdomen, or endoscopy of collateral circulation. Materials and methods: This was a cross-sectional study, with a sample size of 100 patients. Inclusion criteria were patients above the age of 15 years who underwent routine USG abdomen for various conditions in the Radiology Department of a tertiary hospital. Distribution of age, gender, chronic liver disease, portal hypertension, and portal vein diameter of all the patients were measured and recorded. Portal hypertension was diagnosed using the presence of collaterals either on upper endoscopy (if done), Doppler USG, or CT multiphase abdomen. Results: Portal vein diameter of 10.5mm was found to have a sensitivity of 61.22%, specificity of 60.78%, a positive predictive value of 60.00%, a negative predictive value of 62.00%, and accuracy of 61.00%. 45 out of 59 (76.3%) and 37 out of 49 (75.5%) patients of the 50-70 years age group had chronic liver disease and portal hypertension respectively. 45 out of 65 (69.2%) males 37 out of 65 (56.9%) males developed CLD and PHTN. Conclusion: Using portal vein diameter as a diagnostic indicator of PHTN has an accuracy of %, so it can be used in routine USG abdomen of CLD patients to prevent the dreaded complications of PHTN and treat it early. Male gender and patients above the fifth decade were increasingly predisposed to both CLD and PHTN.