The purpose of this study was to determine whether the finding of an enlarged hilar periportal space is a sign for early cirrhosis at magnetic resonance (MR) imaging. Forty-one pathologically proved cirrhotic patients in the early stage of disease who did not show conventional imaging findings of cirrhosis (early cirrhosis group) and 47 patients without history of chronic liver diseases (control group) were included in this study. MR images were qualitatively and quantitatively evaluated for the presence of enlargement of the periportal space. Enlargement of the periportal space was seen in 98% of patients in the early cirrhosis group, while this finding was seen in 11% of patients in the control group (P < 0.0001). The mean value of the hilar periportal fat thickness was significantly greater (P < 0.0001) in the early cirrhosis group (15.5 +/- 6.2 mm) than in the control group (5.3 +/- 3.1 mm). The sensitivity, specificity, accuracy, and positive predictive value of this finding for the MR diagnosis of cirrhosis with a cutoff value of 10 mm were 93%, 92%, 92%, and 91%, respectively. Enlargement of the hilar periportal space is a helpful sign at MR imaging in the discrimination between normal and early cirrhotic livers.