Liver stiffness measurement using FibroScan is a novel rapid and non-invasive technique that evaluates liver fibrosis. In some cases, however, no elasticity measurement is obtained. The aim of this prospective study was to assess the prevalence and factors associated with failure (no value obtained after 10 measurements) of liver stiffness measurement in patients with chronic liver disease. Two thousand one hundred and fourteen liver stiffness measurements were analyzed. Failure was observed in 96 cases (4.5%). Failure was not associated with operator, gender, or transaminase level. By multivariate analysis, the only factor associated with failure was body mass index greater than 28 (odds ratio, 10.0 degrees; 95% confidence interval, 5.7-17.9, P=0.001). In conclusion, liver stiffness is a good method for the evaluation of liver fibrosis that is feasible in more than 95% of patients. Other non-invasive methods such as biochemical methods or liver biopsy could therefore be used only in patients with failure of FibroScan examination.