Recurrence is a tumor renewal in a previously treated field or surgical wound after a disease-free period. The present work investigates loco-regional recurrences. In the first part of the work the most frequent recurrence sites, types and their characteristics (i.e. infiltrating, exophytic, ulcerating) are studied along with the problems in clinical and pathological diagnosis, new diagnostic imaging (CT and MR) and the UICC classification system. The second part of the work is dedicated to examining classical treatments (surgery, radiotherapy, chemotherapy and radiochemotherapy associations) as well new therapies (i.e. cryosurgery, hyperthermia, immunotherapy, photodynamic therapy). A review of the literature is made for indications, results and complications. An extensive study of the cases of the Head and Neck Group of the University of Turin during the 1983-1990 period is also reported. This experience is based on 312 cases: 68 (oropharynx and larynx) treated by surgery, 51 (neck nodes and stomal recurrences) treated by radiotherapy and hyperthermia, 35 (neck nodes) by hyperthermia alone, 168 (all sites) by chemotherapy and 20 by immunotherapy. In the third part of this work supportive therapies and practical problems are reported. In conclusion a therapeutic approach is proposed in relation to the site of the recurrence and previous treatments.