Many mechanical complications associated with insertion, maintenance, and removal of the hemodialysis catheters have been reported in the literature. A 47-year-old man was consulted to our hospital because of an entrapped hemodialysis catheter guidewire. Computed tomographic scan revealed that the right subclavian vein was perforated by the guidewire and the wire was knotted over itself, one loop inside the vein and two loops in the extravascular site. Guidewire is pulled out from a 3-cm incision over the wire loops lateral to the right sternocleidomastoid muscle. He was discharged home on postoperative day 2 without any complication. Our suggestion is that any abnormal resistance should be immediately evaluated for the presence of any potential knots using the most appropriate imaging technique. © 2011 Annals of Vascular Surgery Inc.