Anomalous courses of the left innominate vein have rarely been described in anatomical specimens. Investigative techniques such as angiography and echocardiography have brought to light more instances of this anomaly. Three more cases identified by anatomical study are described. Earlier cases were reviewed to assess the type of associated cardiac malformations. Clinically, the abnormality is regarded as benign. When it is recognised during investigation it should alert the clinician to the possibility of associated malformations. Features commonly seen in tetralogy of Fallot--right aortic arch, ventricular septal defect, and right ventricular outflow obstruction--were common in patients with anomalous subaortic innominate veins.