The hepatic perfusion index (HPI) in patients with hepatocellular carcinoma (HCC) and the correlation between HPI and survival was assessed. From September 1989 to March 1990, 36 patients with HCC and 32 normal volunteers underwent dynamic hepatic scintigraphy to estimate the HPI. Serum alpha-fetoprotein (AFP) and tumour size were also evaluated in all patients. A HPI > or = 0.85, AFP > or = 3000 ng ml-1 and tumour size > or = 8 cm chosen were as the cutoff points to obtain the highest differences in predicting survival. The HPI in HCC patients was significantly higher than in the normal controls (P < 0.0001). Survival was significantly different according to different HPI, AFP and tumour size with P < 0.0001, P = 0.007 and P = 0.01, respectively. It is concluded that the HPI is significantly elevated in patients with HCC. In addition, it is a useful prognostic factor and superior to AFP and tumour size in predicting the survival of patients with HCC.