Per-rectal portal scintigraphy using I-123 IMP was performed before and after TAE in 29 patients with hepatoma. Index of porto-systemic shunt (PSS index) was obtained by lung/(lung + liver) uptake ratio at 30 min after administration of IMP. The influence of TAE on portal circulation was evaluated by using this PSS index. PSS index increased 16 of 29 patients (55.2%) after TAE. PSS index increased after TAE especially in cases of severe liver dysfunction before TAE, marked portal involvement, and embolization of a larger liver volume. PSS index also increased when there was deterioration of esophageal varices, ascites, and hepatic coma after TAE. PSS index is useful for evaluation of portal circulation after TAE.