A two-dimensional (2-D) echocardiographic study was performed on 40 consecutive patients presenting for a routine check-up of their transvenous pacemaker devices, in order to assess the visibility of the intracardiac portion of the pacemaker lead. In 34 patients (85%) the presence of the lead could be demonstrated satisfactorily. In 4 of these 34 patients the entire intracardiac portion of the pacing wire was imaged, in 20 the distal fragment bearing the electrode(s) was seen, and in 10 an intermediate segment was visible. In 6 of the 40 patients (15%) the lead was not visible. In 3 of these 40 patients it was virtually impossible to image any cardiac structure. The less than 100% visibility of the pacing wire may be due to our randomized patient group with a high mean age of 75 years. We conclude that during follow-up examinations or when problems arise in patients with transvenous pacemakers, 2-D echocardiography may be an alternative to roentgenograms, especially if simultaneous information about heart function is desired or septal perforation is suspected. However, chest roentgenograms are still more accurate and remain the technique of choice under normal circumstances.