Scalar electrocardiograms of 31 patients with double-outlet right ventricle (19 with and 12 without pulmonary stenosis) were correlated with the hemodynamic and anatomic findings. Atrioventricular conduction defects, intraventricular conduction delay, and counterclockwise frontal-plane loops were found less often than formerly reported. Counterclockwise frontal-plane loops were found with, as well as without, pulmonary stenosis. The presence or absence of left ventricular hypertrophy did not correlate with the severity of pulmonary vascular obstructive disease. Electrocardiographic evidence of left atrial enlargement was difficult to interpret. Additional intracardiac malformations could not be appreciated from the electrocardiographic findings. The predictive value of the electrocardiogram for the diagnosis of double-outlet right ventricle was considered to be low. In patients with double-outlet right ventricle without pulmonary stenosis, the electrocardiogram was not helpful in predicting the severity of pulmonary vascular obstructive disease.