A patient in whom a left internal jugular vein catheter had first migrated into the left pericardiophrenic vein, and subsequently had perforated into the pericardium leading to a cardiac tamponade is described. Although this malposition has rarely been reported, it does not seem to be so infrequent, as three other similar misplacements have occurred in our institution. This malposition can be prevented by a high degree of suspicion, preferential use of the right internal jugular vein for catheterization, routine use of a J-tipped guidewire, limiting the depth of insertion of the guidewire during cannulation, routine roentgenographic control of radiopaque catheters, and (slow) injection of a small volume of radiopaque dye through the central venous catheter.