This study aimed to investigate the association between the degree of thoracic duct dilatation and the progression of chronic liver disease.In this cross-sectional and retrospective study, 179 patients (mean age, 60.9 years; 114 men) with chronic liver disease who underwent chest CT were enrolled. Dilatation of the left distal thoracic ducts (DTD) was measured and divided into the following 3 grades according to the maximum transverse diameter: grade 0, invisible thoracic duct; grade 1, visible duct with <5-mm diameter; grade 2, diameter of ≥5 mm. Statistical analyses were conducted using the binary logistic regression model.The proportion of grade 2 DTD was notably higher as the chronic liver disease progressed to cirrhosis. Visible DTD on chest CT was significantly related to the presence of cirrhosis (odds ratio [OR], 3.809; P = .027) and significant varix (OR, 3.211; P = .025). Grade 2 DTD was observed more frequently in patients with ascites (OR, 2.788; P = .039). However, 40% of patients with cirrhosis and ascites still exhibited no visible DTD while demonstrating significant amount of ascites, and their ascites were more predominant of recent onset and transient than that observed in other patients (85.7% vs 48.4%, P = .010 and 66.7% vs 29.0%, P = .009, respectively).The degree of thoracic duct dilatation is significantly associated with progression to cirrhosis and advancement of portal hypertension. Further, insufficient lymph drainage to DTD might contribute to the development of ascites.