Christopher Day is Pro-vice Chancellor of the Faculty of Medical Sciences at Newcastle University. He has made key contributions in both cardiology and hepatology. In Cardiology He was the first to describe the relationship between risk of sudden death and QT interval prolongation and his work on QT interval dispersion is now routinely applied in clinical practice. In hepatology his work is very influential in our understanding of genetic susceptibility to alcoholic and drug-induced liver disease and the aetiology of alcoholic and non-alcoholic fatty liver disease and the inter-relationship of the latter with metabolic syndrome, diabetes and obesity. His research has informed our understanding of the natural history of non-alcoholic fatty liver disease and described the ‘two-hit theory’ of progression from benign disease to progressive inflammation and fibrosis. His work has contributed to the recognition of a major new ‘epidemic’ of chronic liver disease and cirrhosis in Western Society.