Background: Chronic liver failure is associated with high signal abnormalities in the basal ganglia on Tl-weighted magnetic resonance imaging of the brain. These abnormalities are strikingly similar to those seen following manganese intoxication. As dietary manganese is normally cleared by the liver, we hypothesize that hepatic dysfunction could lead to manganese overload and account for the MR1 abnormalities seen in patients with chronic liver disease. Methods: We measured blood manganese concentrations in eleven patients with biopsy-proven hepatic cirrhosis and eleven healthy age and sex-matched controls. We also performed semi-quantitative measures of Tl signal abnormalities on MRI in the patients with chronic liver disease. Results: Patients with cirrhosis had significantly higher blood manganese concentrations (20.6 ± 10.2 mcg/L) than controls (7.2 ± 2.7, p = .0013). In addition, semi-quantitative scores of TI-weighted signal hyperintensity on MRI correlated with blood manganese concentration in patients with cirrhosis (r = .65, p = .029). Conclusions: These findings demonstrate that chronic liver disease is associated with manganese overload and suggest that manganese is responsible for the Tl-weighted signal hyperintensity seen on MRI of patients with liver disease. As manganese intoxication is known to cause parkinsonism and an encephalopathy similar to those which occur with chronic liver disease, it is possible that manganese toxicity contributes to the development of these symptoms in liver damaged patients and that therapies which prevent or reduce manganese overload may have clinical benefit.