Inchin-ko-to (ICKT) prevents Fas-mediated liver injury. This study evaluates the effect of ICKT on conventional markers of liver function (LF) and liver fibrosis in 18 postoperative biliary atresia (BA) patients aged 3 to 23 years with elevated glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), gamma-glutamyl transpeptidase (gammaGTP) but normal serum total bilirubin (T-Bil) levels. ICKT (0.15 g/kg per day) was administered orally for 1 year. Serum GOT, GPT, gammaGTP, total bile acids (TBA), and T-Bil as markers of LF and hyaluronic acid (HA), prolyl hydroxylase (PH), procollagen III peptide (PIIIP), and type IV collagen as markers of liver fibrosis were measured before and after treatment in each patient and compared statistically. All patients tolerated ICKT well, and there were no side effects. The percentage of subjects who improved after ICKT was 45% for serum GOT, 72% for GPT, 72% for gammaGTP, 72% for TBA, 67% for HA, 40% for PH, 50% for PIIIP, and 23% for type IV collagen. Changes in the mean values of all serum markers were statistically significant (P < 0.01). It is concluded that long-term administration of ICKT in postoperative BA patients improves liver status as assessed by markers of LF and fibrosis.