The complexity of congenital heart disease has been primarily stratified on the basis of surgical technical difficulty, specific diagnoses, and associated outcomes. We report on the refinement and validation of a pediatric echocardiography complexity (PEC) score. The American College of Cardiology Quality Network assembled a panel from 12 centers to refine a previously published PEC score developed in a single institution. The panel refined complexity categories and included study modifiers to account for complexity related to performance of the echocardiogram. Each center submitted data using the PEC scoring tool on 15 consecutive inpatient and outpatient echocardiograms. Univariate and multivariate analyses were performed to assess for independent predictors of longer study duration. Among the 174 echocardiograms analyzed, 68.9% had underlying congenital heart disease; 44.8% were outpatient; 34.5% were performed in an intensive care setting; 61.5% were follow-up; 46.6% were initial or preoperative; and 9.8% were sedated. All studies had an assigned PEC score. In univariate analysis, longer study duration was associated with several patient and study variables (age <2 years, PEC 4 or 5, initial study, preoperative study, junior or trainee scanner, and need for additional imaging). In multivariable analysis, a higher PEC score of 4 or 5 was independently associated with longer study duration after controlling for study variables and center variation. The PEC scoring tool is feasible and applicable in a variety of clinical settings and can be used for correlation with diagnostic errors, allocation of resources, and assessment of physician and sonographer effort in performing, interpreting, and training in pediatric echocardiography.