Ventricular wall motion as studied with contrast ventriculography has been judged normal in the few previously reported cases of patients with left bundle branch block who have neither coronary artery disease nor diffuse cardiomyopathy. However, recent echocardiographic studies have demonstrated a high frequency of segmental asynergy of the septal wall in such patients. In this study left ventricular wall motion was analyzed in 15 patients with left bundle branch block and without significant coronary artery disease or diffuse cardiomyopathy. Biplane cineangiograms from these patients were compared with those from 100 consecutive patients with normal intraventricular conduction and without coronary artery disease or cardiomyopathy using two techniques: qualitative visual inspection and a computer-assisted quantitative method. By qualitative review, 6 of 15 patients with left bundle branch block had regional akinesia or dyskinesia as compared with none of 100 patients with normal intraventricular conduction (chi square = 42.3; P less than 0.001). By quantitative review, 10 of 12 patients with left bundle branch block had abnormal wall motion along at least one hemiaxis. It is concluded that angiographic regional wall motion abnormalities are common in patients with left bundle branch block, even in the absence of coronary artery disease or diffuse cardiomyopathy. The abnormalities may result from the abnormal sequence of ventricular activation rather than from myocardial fibrosis.