Transient elastography [FibroScan (FS)] is a rapid, noninvasive, and reproducible method for measuring liver stiffness, which correlates with the degree of liver fibrosis in patients with chronic hepatitis. Whether FS is useful in the detection of preexisting liver fibrosis/cirrhosis in patients presenting with acute liver damage is unclear. Patients with acute liver damage of different etiologies were analyzed. Liver stiffness was measured during the acute phase of the liver damage and followed up to the end of the acute phase. A total of 20 patients were included in the study. In 15 of the 20 patients, initial liver stiffness values measured by FS during the acute phase of the liver damage were suggestive of liver cirrhosis. However, none of these 15 patients showed any signs of liver cirrhosis in the physical examination, ultrasound examination, or liver histology [performed in 11 of 15 (73%) patients]. A significant difference was observed in the initial bilirubin levels (5.8 ± 6.5 mg/dL versus 15.7 ± 11.8 mg/dL; P = 0.042) and age (32.4 ± 17.5 years versus 49.7 ± 15.8 years; P = 0.042) between patients with liver stiffness below or above 12.5 kPa. Six patients with initially high liver stiffness were followed up to abatement of the acute hepatitic phase; in all of them, liver stiffness values decreased to values below the cutoff value for liver cirrhosis. Conclusion: Transient elastography frequently yields pathologically high values in patients with acute liver damage and is unsuitable for detecting cirrhosis/fibrosis in these patients. (HEPATOLOGY 2007.)