The field of cardiac pacing has grown extensively over the last 25 years. Permanent cardiac pace- maker implantation has become the established treatment for management of heart block and bradyarrhythmias. The oldest pacemakers were large, bulky units. Since then both the indications and the technology have changed considerably. This unbridled growth of a highly technological field has led to the use of smaller, microprocessor based. sophisticated, longer lasting and "Smart" pacemakers that can pace either or both chambers of the heart, are multiprogrammable and make available to the clinician data on both the patient and the performance of the device. Patient survival has improved both quantitatively and qualitatively due to establishment of AV synchrony and the greater hemo-dynamic benefit from the newer types of dual chamber pacemakers. It provides the clinician with clear and concise analysis of the indications, types and practical management of modern cardiac pacemekers. The questions the clinician faces today are not only about who requires pacing, but about what type of pacemakers will be most beneficial to the patient. For the most part, the discussion will be limited to pacemaker use in patients with bradyarrhythmias. Devices for treatment of tachyarrhythmias are becoming more and more available, but they are still investigational.