Cardiac catheterization using the transradial access has been proven to be safe, but can be complicated in some cases by catheter kinking or knotting. This complication is often the result of excessive manipulations due to the S-shaped configuration of the right subclavian-innominate-aorta axis. When a knot occurs in the brachial artery, regular maneuvers to unknot the catheter can be unsuccessful due to the narrow diameter of the artery or to the failure of the external fixation of the distal part of the catheter. We present a case of a knotted catheter in the brachial artery, untwisted with a snare technique. This endovascular technique is simple and avoids surgical extraction.