Purpose To evaluate the diagnostic accuracy of shear-wave elastography (SWE) in identifying different degrees of fibrosis in a cohort of consecutive children and adolescents with nonalcoholic steatohepatitis (NASH). Materials and Methods Consecutive pediatric patients scheduled to undergo liver biopsy were studied with an ultrasonography-based SWE system. Elastography was performed in 68 of 69 patients with biopsy-proved NASH (37 boys and 31 girls; mean age, 12.6 years ± 2.48; age range, 8-17 years). The correlations among laboratory findings, liver stiffness, and fibrosis score were analyzed, and the area under the receiver operating characteristic curve (AUC) was used to assess the presence of any fibrosis (score ≥F1) or significant fibrosis (score ≥F2). Findings from histologic examination were used as the standard of reference. Results SWE showed a very high correlation with liver fibrosis (P < .001) at univariate and multivariate analyses. The AUCs for the association of any and significant fibrosis were 0.92 (95% confidence interval [CI]: 0.86, 0.98) and 0.97 (95% CI: 0.95, 0.99), respectively. The intraclass correlation coefficient for absolute agreement was 0.95 (95% CI: 0.90, 0.97). Conclusion SWE is an accurate and reproducible noninvasive technique that efficiently depicts the presence of significant liver fibrosis and, less accurately, mild liver fibrosis in pediatric patients with nonalcoholic fatty liver disease. Larger clinical prospective studies are warranted to confirm SWE accuracy and establish threshold values for fibrosis grading in comparison or in combination with other noninvasive methods. © RSNA, 2016.