Sentinel node biopsy is being increasingly used as a staging tool for mucosal head and neck cancer. This review of the literature summarizes the results of research into the procedure when it has been performed in three main contexts: as part of an ipsilateral neck dissection, as a stand-alone procedure to stage the neck for positive or negative disease, and as a means of investigating the non-involved or contralateral neck in tumors close to or crossing the midline. The role of the procedure is discussed and the difficulties encountered are expanded, with a particular emphasis on pitfalls of the technique, caveats, and its potential role for the future.