Currently, liver biopsy is still regarded as the gold-standard in the diagnosis of non-alcoholic fatty liver disease and monitoring of progression. However, accuracy of diagnosis is not perfect with a certain risk of sampling error depending on biopsy quality and a more or less homogeneous distribution of liver tissue alterations. Complications are rare; however, the method is invasive and carries the risk of bleeding. Therefore, non-invasive methods (such as serum biomarkers or imaging techniques) are sought for accurate diagnosis and safe monitoring of disease progression. Unidimensional transient elastography (TE; FibroScan®) is a non-invasive technique, which can be a helpful tool here: however, accuracy of diagnosis is depending on the stage of fibrosis and lower grades of fibrosis (stage 1 and 2) are difficult to assess. Moreover, in obese patients this method cannot be applied.