Abstract Introduction: Non-alcoholic fatty liver disease (NAFLD) and Non-alcoholic Steatohepatitis (NASH) are common conditions, affecting about one third of the adult population. Important sequelae include liver cirrhosis, primary hepatocellular carcinoma and end stage liver disease. NAFLD and NASH are usually asymptomatic and population estimates indicate a large burden of disease. Management of early stage asymptomatic disease is by lifestyle intervention to address known risk factors including obesity and type 2 diabetes mellitus. This study aimed to estimate the known prevalence of NAFLD and NASH in a representative UK primary care database, to establish the quality of management by assessing the proportion of cases who received lifestyle advice and to examine which factors are associated with receiving advice.Study Method: We interrogated a UK primary care database using diagnostic code ontology lists to determine epidemiological parameters and to compile descriptive statistics for prevalence and proportion of patients receiving lifestyle advice. A logistic regression model was fitted to the data to determine independent variables associated with receiving different types of lifestyle advice.Results: The recorded prevalence of NAFLD (~0.4 %) and NASH (~ 0.06%) is much lower than in similar countries and is increasing year on year. 30% of patients received lifestyle advice, but the variables associated with an increased likelihood of receiving that advice were appropriate.Conclusions: There is a large prevalence gap with respect to NAFLD and NASH, implying a huge hidden burden of disease. These results are similar to estimates recently published by the Lancet Liver Commission, contributed by the RCGP RSC. More research would help determine an accurate figure for this burden. Current primary care management of NAFLD and NASH is appropriate in scope, but lacking in coverage. Initiatives and further research to address both the hidden burden of disease and likely future cost should be considered.