Purpose. In order to provide more information for the clinician and to analyse the role of twice-a-day radiotherapy on the specific overall survival (OS), disease-free survival (DFS), local disease-free survival (LDFS), metastasis free survival (MFS) and toxicity, a retrospective study of head and neck cancer at Institut Català d¿Oncologia has been undertaken. Patients and methods. From 1992 to 1999, 373 patients were selected for this study with a median follow-up period of 20.96 months (range 9-95). Mean age of the patients was 57 years (range 18-85). Stages were distributed as follows: 66 patients in stage II (17.7%), 100 in stage III (26.8%) and 198 (53,1%) in stage IV. Twice-a-day radiotherapy was administered to head and neck cancer with a curative intent in all patients. Three hundred and fifty-seven patients received 1.2 Gy per fraction with a 6-hour interfraction interval, and 15 patients received 1.6 Gy per fraction with the same interval. The primary site in most patients was the oropharynx, hypopharynx, or larynx. All patients received radiotherapy to the primary site, with or without planned neck dissection after radiotherapy. Induction chemotherapy was used in same indications. Surgery at the primary site was reserved for salvage of radiotherapy failures. Mean given dose was 79.14 Gy (range 64.80-84) with twice-a-day external radiation therapy. One hundred and sixty-nine patients (45.30%) received induction chemotherapy as part of the initial treatment plan. Univariate and multivariate analysis has been carried out. Results. OS for the entire group was 71.57% at 2 years and 58.76% at 5 and 8 years. Probability of DFS was 68.34% at 2 years, 53.95% at 5 years and 48.53% at 8 years. The LDFS was 72.84%, 60.26% and 54.20% at 2, 5 and 8 years respectively. The MFS probability was 88.14%, 82.27% and 78.35% at 3, 5 and 8 years respectively. Multivariated analysis to OS demonstrate that localization (oropharynx, hypopharynx, supraglottis, rinopharynx, and glottis in growing order of survival), stage (IV, III and II in growing order of survival), and feeding through a nasogastric tube (with and without in a growing order of survival) were prognostic factors. Multivariated analysis for DFS demonstrate that patients with a stage III and IV, oropharynx localization and patients that received feeding through a nasogastric tube were prognostic factors. Multivariated analysis for LDFS demonstrated that localization (oropharynx, hypopharynx, supraglottis, glottis and rinopharynx in growing order of survival), stage (IV, III and II in a growing order of survival) and total dose (in a growing survival order: less or equal to 78.4 Gy, superior to 80.4 Gy, between 79.4 and 80.4 Gy, and between 78.4 and 79.4 Gy) remains as a prognostic factors. Multivariated analysis for MFS demonstrate that localization (glottis versus supraglottis, oropharynx, rinopharynx, hypopharynx) was a prognostic factor. Mucosal toxicity was frequent (87.9% = grade III) but manageable. Thirty percent of patients required feeding tube. Conclusion. We conclude that patients with head and neck cancer undergoing twice-a-day external radiotherapy can be effectively managed. Overall survival and long-term local control are excellent and toxicity is acceptable.