The TNM system is an established tool for classification of solid tumors by means of tumor size and extent, the involvement of local lymph nodes, and the presence of distant metastases. The classification was established in order to visualize prognostic implications and to allow establishment of systematic therapeutic algorithms. Since the beginning of 2017 a revised version of the classification has applied. Particularly the classification of otorhinolaryngologic tumors has been thoroughly revised in the 8th edition, partly on the basis of new prognostically relevant parameters, such as infection with oncogenic human papillomavirus (HPV) subtypes. The 8th edition of the American Joint Committee on Cancer (AJCC) served as a basis for the review. The highlighted changes were supplemented by a literature review and the most important elements were summarized. Substantial changes were made for oropharyngeal carcinomas caused by HPV, for the classification of lymph node metastases under consideration of extranodal extension, and for classification of tumors of the oral cavity. Due to their frequency and special biology, skin tumors in the head and neck area are now described in a separate chapter. The new classification is a challenge for all specialties involved in tumor staging and therapy. The advantage for the patient lies in a more accurately adjustable treatment modality through more precise classification of tumors. Good collaboration and rapid implementation of the new classification is required in all disciplines involved in head neck tumor diagnostics and therapy.