The argyrophilic technique for staining proteins associated with nucleolar organizer regions (AgNOR's) was applied to 32 liver biopsy specimens. These included 10 normal livers, 10 cirrhosis, 10 hepatocellular carcinomas (HCC) and 2 cholangiocarcinomas. The range of the mean number of NORs per nucleus was 1.3-1.7 (95% CI: 1.4-1.6) for normal liver, 2.4-3.5 (2.8-3.2) for cirrhosis, 3.0-7.9 (3.7-5.6) for HCC and 4.0-4.2 (3.9-4.3) for cholangiocarcinoma. The difference observed was statistically significant. The AgNORs were small and discrete in normal and cirrhotic liver and relatively larger and scattered in distribution in HCC. These results indicate that both quantitative and qualitative analysis of AgNORs may be useful as an adjunct to routine haematoxylin and eosin stain to distinguish cirrhosis from HCC especially when the latter is well differentiated.