Patients with chronic hepatitis C virus (HCV) infection frequently describe neuropsychological symptoms. Although hepatic encephalopathy is the best established neurological association of HCV infection, there is a growing body of literature on cerebral dysfunction, occurring at an early stage of chronic HCV infection, well before the development of cirrhosis. In this review we describe recent studies that have documented mild, but significant neurocognitive impairment in HCV infection. These deficits in patients with minimal or absent liver disease do not appear to be attributable to a history of substance abuse, coexistent depression or hepatic encephalopathy. Recent studies employing in-vivo magnetic resonance spectroscopy have suggested that a biological mechanism associated with the virus may be responsible. The hypothesis that HCV infection of the central nervous system may be related to the reported neuropsychological symptoms and cognitive impairment is supported by molecular virological studies of post-mortem brain tissue.