목적: Cachexia is a debilitating condition that affects clinical course and demise of cancer patients. The purpose of study was tTo identify the prevalence of cancer cachexia and its impact on the prognosis of the patients with advanced head and neck cancer (HNC). 방법:From 2006 to 2012, a total number of 361 advanced HNC patients who were diagnosed and treated in our hospital was included. Prevalence of cancer cachexia was analyzed according to the time sequences of treatment. Correlations between patients characteristics and cachexia were evaluated. Recurrences, second primary cancer developments, noncancer health events, and cause-specific survivals were analyzed according to the incidence of cancer cachexia on above specific periods of follow-up. 결과:Cancer cachexia was identified in 22 (6.1%), 148 (41%), 66 (18.3%), and 65 (18%) patients at pretreatment, immediately after-, 6 months after-, 12 months after treatment, respectively. Patients received initial treatment including chemotherapy and with non-laryngeal primary tumor sites had more risk of cachexia at immediately after treatment (P</i> <0.05). At 12 months after treatment, patients with older age and advanced T stage more frequently suffered from cachexia (P</i><0.05). Patients with cachexia at pretreatment, 6 and 12 months after treatment had significant more risks of recurrences and all-causes of mortalities (i.e., overall and cancer-specific). 결론:Patients with advanced HNC showed relatively high prevalence of cancer cachexia. Cachexia still existed on 6- and 12 months after treatment implied higher chance of recurrences and deaths, therefore, careful monitoring and interventions would be necessary to these patients.