Transient elastography (TE) has received increasing attention as a means to evaluate disease progression in chronic liver disease patients. In this study, we assessed the value of TE for the prediction of fibrosis stage in a cohort of pediatric patients with nonalcoholic steatohepatitis. Furthermore, TE interobserver agreement was evaluated. TE was performed in 52 consecutive biopsy-proven nonalcoholic steatohepatitis patients (32 males, 20 females, age 13.6 +/- 2.44 years). The area under the receiver operating characteristic curves for the prediction of "any" (>or=1), significant (>or=2), or advanced fibrosis (>or=3) were 0.977, 0.992, and 1, respectively. Calculation of multilevel likelihood ratios showed that TE values <5, <7, and <9 kPa, suggest the presence of "any" fibrosis, significant fibrosis, and advanced fibrosis, respectively. TE values between 5 and 7 kPa predict a fibrosis stage of 1, but with some degree of uncertainty. TE values between 7 and 9 kPa predict fibrosis stages 1 or 2, but cannot discriminate between these two stages. TE values of at least 9 kPa are associated with the presence of advanced fibrosis. The intraclass correlation coefficient for absolute agreement was 0.961. TE is an accurate and reproducible methodology to identify pediatric subjects without fibrosis or significant fibrosis, or with advanced fibrosis. In patients in which likelihood ratios are not optimal to provide a reliable indication of the disease stage, liver biopsy should be considered when clinically indicated.