With expanding indications for device therapies for management of cardiovascular diseases, the number of patients receiving pacemaker implantations are increasing every year. These cardiac electronic devices rely on complex microcircuitry and use electromagnetic waves for their communication with the programmers. Therefore, they are susceptible to interference from the surrounding electromagnetic radiation. Electromagnetic interference (EMI) can be defined as any signal, either biologic or non-biologic, that falls within a frequency spectrum that are being detected by the sensing circuitry of the pacemaker. They can interfere with the optimal function of the pacemaker and is always a concern for the patients with a pacemaker, since the risk of EMI is greatest in pacemaker dependent patients. EMI may potentially affect a pacemaker in one of three ways: Stopping the pacemaker from delivering the stimulating pulses that regulate heart's rhythm; causing the pacemaker to deliver the irregularly; and causing the pacemaker to ignore heart's own rhythm and deliver pulses at a fixed rate. EMI with pacemakers can be very complex, not only from the technical standpoint, but also from the view of public health issues. Pacemakers may be affected by various equipments in our daily life, varying from hospital equipments to security devices. Hospital procedures like electrocautery, cardioversion, defibrillation, magnetic resonance imaging, lithotripsy, radiofrequency ablation, diathermy etc., may interfere with the normal pacemaker function. Similarly other electromagnetic equipments like cell phones, digital media players (MP3, ipod etc.,) security devices, anti theft devices, conduction heaters, microwave ovens, welding equipments may also interfere with the pacemaker. Complete avoidance of these equipments may not be practical for most of the patients with pacemaker and this may significantly affect the quality of life too. Hence, patients with these devices should be advised to employ certain recommended changes so that they can enjoy the full benefits of the pacemaker. It is important that the clinician taking care of a patient with implanted device be aware of these resources and to provide appropriate education and protection to the patient. In this chapter, we will discuss about the various interferences with the pacemakers in day to day activities of the patients and the methods to tackle them.