Discussions on the complications of central venous catheterization in children typically focus on infectious and the more common mechanical complications of pneumothorax, hemothorax, or thrombosis. Rare complications are often more life-threatening, and inexperience may compound the problem. Central venous catheter complications can be broken down into early or late, depending on when they occur. The more serious complications are typically mechanical and occur early, but delayed presentations of pericardial effusions, cardiac tamponade, and pleural effusions may be of equal severity, and delay in diagnosis can be catastrophic. Careful insertion techniques, as well as continued vigilance in the correct position and function of central venous catheters, are imperative to help prevent serious complications.