Four hundred and fifty‐five patients over age 65 with atrioventricular and intraventricular conduction defects were studied for periods of from two to five years (average, twenty‐six months). Data on the overall incidence of conduction defects, the sex incidence, the type of block, and the associated electrocardiographic abnormalities are presented. There was no ECG evidence of extension of the blocks based on prolongation of the P‐R interval, a shift or an increase in axis, a shift of the block from one branch to another, or an increase in width of the QRS complex. Left bundle‐branch block and left anterior hemiblock, either alone or in association with any other fascicular block, were more common in the female patients whereas right bundle‐branch block was more common in the male patients.