Central venous access remains an integral part of perioperative and intensive care, and several methods have been described to locate the internal jugular vein (IJV) prior to cannulation. The apex of Sedillot's triangle between the manubrial and clavicular heads of the sternocleidomastoid (SCM) muscle is a commonly used anatomical landmark for a central percutaneous approach to the IJV, but the literature highlights failures and complications when adopting this method. This cadaveric study was designed to investigate the usefulness of Sedillot's triangle to locate the IJV. Sixty-one cadavers were used for investigation at the University of Cambridge Human Anatomy Centre. Sedillot's triangle was dissected and a pin was inserted in a sagittal plane at the apex of the triangle. The location of the pin in relation to the IJV was recorded. The distance between the sternal and clavicular heads of SCM was also measured. In total, the pin inserted at the apex of Sedillot's triangle pierced the IJV in 72/117 (61.5%) of dissections, with 71.4% on the right and 52.5% on the left. There was important variation in SCM anatomy, and there was no gap between its two heads in 12% of the neck dissections. We demonstrate an overall poor success rate of the central percutaneous approach using Sedillot's triangle, although our findings are limited being a simulated cadaveric study. We support education and use of ultrasound in addition to landmark techniques to aid the safe insertion of central venous catheters.