Portal hypertension leads to the formation of portosystemic collateral veins in cirrhosis of liver. Rupture of esophageal varices is common and can be fatal. Although ammonia plays a certain role in determining portosystemic encephalopathy, the venous ammonia level has not been found to correlate with the presence or severity of this entity. So, this concept has become partially obsolete. Realizing the need for noninvasive markers mirroring the presence of esophageal varices in order to reduce the number of endoscopy screening, this study is aimed to determine whether there is a correlation between blood ammonia concentrations and the size of esophageal varices. This was a cross-sectional study conducted upon 40 consecutive cirrhosis patients and 40 age-matched noncirrhotic control subjects. Fasting blood ammonia was measured in both groups and upper gastrointestinal endoscopy was done in cirrhotic patients to note different sizes of esophageal varices. Cirrhosis patients group had mean ammonia level of 84.88 mol/l compared to 28.47 mol/l in control group (p < 0.05). The mean (± SD) blood ammonia concentration in small esophageal varices group was 72.00 (± 39.13) mol/l and that in medium or large esophageal varices group was 97.75 (± 31.34) mol/l. The difference was significant at p-value <0.05 level. Among blood ammonia, platelet count and spleen longitudinal diameter (SLD) on ultrasonography (USG), only ammonia level positively correlated with size of varices (p = 0.004). There was a moderate but significant correlation between blood ammonia level and size of esophageal varices. So, this could be a good tool for identifying individuals with large esophageal varices who will need to undergo endoscopy more frequently.