To compare the appropriateness and diagnostic yield of initial outpatient transthoracic echocardiography (TTE) between a community pediatric cardiology practice and an academic children's hospital. Initial outpatient pediatric TTE ordered by pediatric cardiologists between January and March 2014 at a community practice (Packard Children's Health Alliance PCHA; n = 238) and an academic tertiary center (Lucile Packard Children's Hospital LPCH; n = 76) were evaluated based on appropriate use criteria (AUC) released in December 2014. Multivariate logistic regression was used to identify predictors of “rarely appropriate” indications and abnormal TTE findings. Of 314 TTEs, 165 (52.5%) were classified as “appropriate,” 40 (12.7%) were classified as “may be appropriate,” 100 (31.9%) were classified as “rarely appropriate,” and 9 (2.9%) were unclassifiable. The proportion of abnormal findings did not differ between the 2 practice settings (5.3% for LPCH vs 7.6% for PCHA; P = .61). TTEs performed at PCHA were significantly more likely to be “rarely appropriate” (OR, 2.57; 95% CI, 1.28-5.15; P = .008). Children aged <1 year (OR, 1.90; 95% CI, 1.03-3.50; P = .04) and ordering providers with <10 years since the completion of their fellowship (OR, 2.15; 95% CI, 1.20-3.87; P = .01) were associated with “rarely appropriate” indications. “Appropriate” TTEs were associated with abnormal findings (OR, 8.69; 95% CI, 1.77-42.68; P = .008). The community practice was independently associated with greater inappropriate ordering of initial outpatient pediatric TTEs compared with the academic practice. The assessment of practice patterns following AUC release should account for physician and practice-related factors that could influence differences in TTE ordering patterns.