Among 36 patients with univentricular atrioventricular connections, 27 had left ventricular and 9 right ventricular morphology. None had a common or indeterminate ventricle on autopsy review. Angiographic analysis correctly determined ventricular morphology in 34 (94%) of 36 patients. All 9 patients with right ventricular morphology of the dominant ventricular chamber were correctly identified angiographically. Altogether 25 of 27 patients (93%) with left ventricular morphology of the dominate ventricular chamber were correctly identified angiographically. Two patients with left ventricular morphology and severely dilated ventricles were incorrectly classified as having right ventricular morphology by angiographic assessment. For patients with a single functional ventricle, we conclude that angiographic assessment is an excellent method for determining ventricular morphology.