The clinical significance of and discrepancy between the indocyanine green retention rate at 15min (ICGR15) and liver activity at 15min (LHL15) by technetium-99m galactosyl human serum albumin ( [Formula: see text] -GSA) scintigraphy and clinical outcome were examined in 140 patients who underwent hepatectomy. Both ICGR15 and LHL15 were significantly associated with portal pressure and liver function tests, fibrotic degree and regeneration of the remnant liver ( [Formula: see text] ). The significance of the correlation between LHL15 and liver functions and HAI score appeared to be better than that with ICGR15. A significant correlation was observed between ICGR15 and LHL15 ( [Formula: see text] 0.591, [Formula: see text] ) for all but 12 patients (8.6%). Of three patients with LHL15 better than ICGR15, two had obstructive jaundice and one had an intrahepatic shunt. Patient outcome was relatively good. In nine patients with LHL15 worse than ICGR15, the HAI score was higher (=7) and six of the nine had hepatic failure or uncontrolled ascites. Complications were frequently observed in patients with LHL15 below 0.875 (80% versus 30%, [Formula: see text] ). Our results indicate that [Formula: see text] -GSA scintigraphy is a reliable auxiliary test of hepatic functional reserve combined with ICGR15 for selecting the extent of hepatectomy and predicting patient outcome.