Objectives: Perforation of heart chambers is one of the rare complications observed during electrophysiological studies and placement of pacemaker leads. In this study, we performed a retrospective evaluation of patients with catheter-related right heart perforation, aiming to determine its incidence and clinical course. Study design: We reviewed cases with catheter-relater cardiac perforations observed at our institution from June 2002 to November 2007. Results: During the study period, a total of 2,385 procedures were performed (1,287 electrophysiologic studies, 1,098 temporary nonballoon-floating pacing lead placements). Eight cardiac perforations were diagnosed, with the overall procedure-based and catheter-based incidences of 0.34% (8/2,385) and 0.14% (8/5,603), respectively. Three of these perforations were related to diagnostic electrophysiology catheters, and five were related to temporary (1 permanent) transvenous pacemaker leads. Seven perforations involved the right ventricle and one involved the right atrium. Three patients in whom right ventricular perforation was detected at a late stage died suddenly after pacemaker lead implantation. One patient underwent surgical exploration because of right atrial perforation. Two patients underwent coronary bypass operation and, in one of these patients, perforation was detected during surgery. Two patients were managed conservatively. Conclusion: Although right ventricular perforations detected early have a relatively benign course, those detected late and right atrial perforations require emergent surgical exploration and may have catastrophic consequences. © 2011 Turkish Society of Cardiology.