Electrocardiography is often advocated as a screening tool in children for hypertrophic cardiomyopathy (HC). We sought to establish an electrocardiographic screening tool to identify children with HC. We hypothesized that a pediatric-specific electrocardiographic criterion would perform better than the popular criteria used for screening children for left ventricular hypertrophy and HC. The earliest available electrocardiogram for children (n = 108) with HC (ages 7 to 21 yrs) was reviewed. We sought to compare the diagnostic accuracy of 4 screening algorithms: (1) Sokolow-Lyon criterion (SV₁ + RV₅/RV₆ >35 mm), (2) Cornell criterion (RaVL + SV₃ >28 mm in men, 20 mm in women), (3) total 12-lead voltage criterion (R wave to the nadir of Q/S wave >175 mm), and (4) pediatric-specific criterion (RaVL + SV₂ >23 mm). The same criteria were applied to a cohort of age-matched and gender-matched controls without cardiac disease. Statistically significant correlations were found between children with HC and positive screen using all 4 criteria. However, comparison of receiver operating characteristic demonstrated an area under the curve of 0.67 for Sokolow-Lyon criterion, 0.70 for Cornell criterion, 0.83 for total 12-lead criterion, and 0.82 for pediatric-specific criterion. Pediatric-specific criterion had superior sensitivity in gene-positive children and superior overall specificity than total 12-lead criterion. In conclusion, our study demonstrates that the pediatric-specific criterion employing leads RaVL + SV₂ is more accurate in identifying children with HC in comparison with other popular screening criteria.