We present a case of cardiac tamponade associated with placement of a central venous catheter (CVC) via a peripheral vein in a 14-year-old girl with idiopathic scoliosis undergoing corrective surgery. A number of complications have been described in association with CVC misplacement. Sporadic cases of cardiac tamponade from this have been reported, but the actual incidence is unknown. Death from cardiac tamponade attributed to CVCs ranges from 65 to 100%. In our patient, cannulation of the pericardiophrenic vein was probably the cause of cardiac tamponade, based on radiological evidence that the initial location of the catheter was near the right atrium and possibly at the outlet of the pericardiophrenic vein. The catheter could have advanced into the vein and then to the pericardial sac with postural changes. The acute clinical course of cardiac tamponade in our patient had potentially lethal hemodynamic repercussions. The main diagnostic test for this condition is echocardiography and the only effective treatment is drainage of the pericardial effusion. Echocardiography should be performed before pericardiocentesis except in life-threatening situations or high clinical suspicion. Although they are rare, it is important to be aware of the potential for CVC complications.