Concurrent chemoradiotherapy (CCRT) is the standard approach for the treatment of locally advanced head and neck squamous cell carcinoma. Despite its undisputed advantages, CCRT is associated with acute and late toxicities, leading to unfavorable implications (eg, unplanned interruptions and noncancer-related mortality). The former prolongs the overall treatment time leading to a detrimental effect on tumor control. The latter consists of several noncancer morbidities arising from treatment-related toxicities, identifying a new pathway in cancer fate. This pathway has been termed noncancer mortality or competing mortality and consists of a series of treatment-competing morbidities, which nullify all therapeutic efforts aimed at curing these patients. The management of patients with head and neck squamous cell carcinoma who experience treatment-related toxicities is complex and requires expertise in oncological treatment as well as supportive care. The optimal management of these patients should start with knowledge regarding the most important competing morbidities developing during all phases of the disease (ie, from diagnosis to follow-up) to minimize treatment interruptions, ensure appropriate psychological support, and achieve the best oncological result. The purpose of the present review is to analyze the most important competing morbidities due to patient’s condition at baseline and CCRT, which could result in noncancer mortality. A multidisciplinary team approach is strongly required in the management of this disease.