The clinical course of 1,022 consecutive patients who received a temporary transvenous pacemaker in the coronary care unit during a 5-year period between January 1976 and January 1981 was reviewed. The route of pacemaker insertion was identified in 942 patients (92.2%) and included antecubital vein cutdown in 606 patients (59.3%), subclavian venipuncture in 177 patients (17.3%), right internal jugular venipuncture in 111 patients (10.9%), and femoral venipuncture in 48 patients (4.7%). Pacemaker-related complications occurred in 140 instances (13.7% morbidity), without associated mortality. The most common complication was the development of a new pericardial rub (54 patients, 5.3%). The right internal jugular approach was associated with the lowest complication rate. On the basis of these findings, it is our practice to insert temporary pacemakers via the right internal jugular or subclavian route.