Liver pathology complicates Fontan palliation. Previous reports established that both hepatic sinusoidal and portal fibrosis occur in patients after Fontan procedures. Past studies predominantly included symptomatic patient cohorts. Thus, the authors of this study aimed to characterize hepatic pathology via transvenous hepatic biopsies in 21 asymptomatic patients at the time of elective cardiac catheterization. Seven of these patients (33 %) were accompanied by an interventional procedure. Hepatic biopsies showed evidence of either sinusoidal or portal fibrosis or both in all but one patient. The findings showed a statistically significant (p = 0.005) moderately strong positive correlation between fibrosis scores and time since Fontan surgery. Additionally, no significant correlation was found between fibrosis scores and inferior vena cava pressure, pulmonary vascular resistance, platelet counts, or serum laboratory testing of hepatic function.