Long-term follow-up of 101 healthy elderly subjects living independently in the community has been undertaken by means of clinical examination, resting ECG and 24-hour ambulatory cardiac monitoring. It appears that the finding of ventricular premature complexes at the rate of 10 per hour or greater is associated with a significant increase in mortality. The prevalence of atrial fibrillation, initially found to be 11%, rises with age to 17% by the age of 84 years. Long-term ambulatory monitoring is essential in the proper documentation of paroxysmal atrial fibrillation. Bundle branch block also occurs in over 10% of elderly people and the prevalence rises steeply with age, so that at the end of this study more than one quarter of the survivors had evidence of His-Purkinje disease. Over 5% of our subjects had definite indications for pacing during the period of follow-up and lends support to the opinion that the current pacemaker implantation rate in the United Kingdom is below the optimal level.