Subclavian vein cannulation may be complicated by lesions of the peripheral nervous system, such as injury to the recurrent laryngeal nerve, phrenic nerve, and brachial plexus. We describe a case of lesion of the upper trunk of the brachial plexus during multiple attempts at subclavian vein catheterization. This type of complication, ascribed to erroneous application of procedures or anatomical variations, may be minimized by abstaining from multiple attempts at venipuncture.