Although transient elastography (TE) is the primary noninvasive method for assessing liver fibrosis, its use remains to be validated in children. This study aims to evaluate the agreement between two-dimensional ultrasound shear wave elastography (2D-SWE) and TE to assess pediatric liver stiffness method. During the 18-month study, we prospectively included 101 consecutive children (median age: 8.5 years, range: 1 month to 17 years) who required TE for medical reasons, and in whom 2D-SWE measurement was performed within a 3-month follow-up during a routine ultrasound. Liver elasticity values were classified according to the Metavir score using published pediatric norms for TE and according to the manufacturer's reference values for 2D-SWE. The Spearman's correlation coefficient was used to assess the relationship between the elasticity measured by the two techniques. Concordance was described by the Bland-Altman method. A strong correlation (rho = 0.70, < 0.001) was found between 2D-SWE and TE for the elasticity measures. The strength of correlation was higher among patients older than 6 years (rho = 0.79, < 0.001). Concordance between liver fibrosis stages assessed by these techniques was moderate [weighted kappa = 0.46, (95% CI: 0.35-0.57)]. When considering stages over F2, 2D-SWE diagnostic performances showed a sensitivity of 85% (95% CI: 74-92) and a specificity of 57% (95% CI: 42-70) compared with TE. Measurements of the liver stiffness using 2D-SWE and TE are strongly correlated. The moderate concordance between these techniques for assessing the liver fibrosis stage provides evidence against alternating between these methods during follow-up of patients with the chronic liver diseases.