A neonate with transient, benign left bundle branch block has been presented. There is no similar case report in the literature. The etiology of the left ventricular conduction delay is unknown, but there was no clinical evidence of a congenital anomaly or of infectious mayocarditis. The finidings of this infant differed from those of adults in that there was wide splitting of the second heart sound throughout the respiratory cycle, no gallop sounds, and the initial forces of the QRS were atypical. These differences are thought to represent the expected findings of LBBB in a newborn.