Background: Esophageal varices is one of the major complications of portal hypertension and one of the main causes of death in cirrhotic patients, so prophylaxis from esophageal varices bleeding can decrease the number of deaths in those patients. Aim of the work: To assess the effect of non-selective beta blockers on portal vein diameter and grades of esophageal varices. Subjects and methods: Our study was carried out at Gastroenterology and Hepatology unit, Internal Medicine department, Zagazig University hospital. Forty patients with HCV positive liver cirrhosis were enclosed in the study. All were Child Pugh grade A and B, diagnosed by clinical examination, laboratory investigations (hepatitis C virus antibody, hepatitis C virus RNA by polymerase chain reaction, hepatitis B virus surface antigen, liver and kidney functions, complete blood count, INR and alpha feto-protein) and pelvi-abdominal ultrasound findings. Upper gastro-intestinal (GI) endoscopy was done at the beginning of the study for detection and grading of esophageal varices (EVs) and those without EVs were excluded, also portal vein diameter (PVD) was recorded by ultrasound. The maximum tolerated dose of Propranolol (decrease pulse rate by 25% but not below 60 beats per minute) was given to all patients for three months. EVs grading, by upper GI endoscopy, and PVD were reassessed at the end of the study. Results: Propranolol showed a significant reduction in heart rate and PVD for the pre and post-treatment results after three months of treatment (P<0.001 for both). The dose of Propranolol didn't show significant effect on reduction of small size EVs (P=0.07) while the percent of reduction of PVD correlated significantly with percent of reduction in EVs grade for the pre and post-treatment (P<0.05).  A cut off point for detection of significant EVs (GII and III) was 12.5 mm with sensitivity 82.4%, specificity 47.8%, positive predictive value (PPV) 53.8% and negative predictive value (NPV) 78.6%.   Conclusion:    Non-selective beta blocker (Propranolol) caused significant reduction in portal vein diameter and the percentage of reduction of portal vein diameter significantly correlated with change in esophageal varices grades.