Head and neck cancers are predominantly squamous cell carcinomas with a high propensity for lymphatic spread, and therefore the lymphatic management forms an integral part of the management of head and neck cancers. A working knowledge of the layout of this lymphatic system and the spread of the cancer therein is essential to the understanding of these cancers. These cancers arise from the mucosa lining the upper aero digestive tract, i.e. the oral cavity, pharynx, larynx and the paranasal sinuses. Cancers of the nasopharynx, oropharynx and pyriform sinus have a much higher incidence of lymphatic involvement while those of the vocal cords and paranasal sinuses have a very low incidence. There are estimated 150–350 lymph nodes in the head and neck region, comprising nearly a third of the total lymph nodes in the body. Most of these nodes are arranged along the internal jugular vein from the base of the skull to the root of the neck. The posterior chain of nodes lies in the posterior triangle along the spinal accessory nerve. These nodes lie in a plane superficial to the prevertebral fascia, an important point to be kept in mind while performing a neck dissection.