The brachial plexus is one of the more challenging anatomical components of the peripheral nervous system to master, even before one picks up a transducer. The significant variation in the formation and arrangement of the plexus makes detailed anatomical knowledge essential to a complete ultrasound study. Ultrasound with its dynamic multiplanar high resolution capabilities allows the examiner to transform the acquired two-dimensional (2-D) anatomy into a more comprehensible three-dimensional (3-D) image.