BackgroundCancers of the head and neck have a high mortality rate, and roughly 10% of the patients die within six months of diagnosis. To our knowledge little has been written about this group.We wished to identify risk factors for early death, to predict and monitor patients at risk better and, if possible, avoid unjustified major treatment.Methods and findingsThis population-based nationwide study from the Swedish Head and Neck Cancer Register (SweHNCR) included data from 2008–2015 and 9733 patients at potential risk of early death.A total of 925 (9.5%) patients died within six months. For every year older the patients became, the risk of early death increased by 2.3% (p<0.001). The relative risk of death was 3.37 times higher (237%) for patients with WHO score 1 compared with WHO score 0. A primary tumour in the hypopharynx correlated with a 24% increased risk over the oral cavity (p<0.024). Patients with stage IV disease had a 3.7 times greater risk of early death than those with stage I (p<0.001). As expected, a 12 times increased risk of early death was noted in the palliative treatment group, compared to the curative group.Limitations to this study were that the actual cause of death was not recorded in the SweHNCR, and that socioeconomic factors, alcohol consumption, smoking habits, and HPV status, were not reported in SweHNCR until 2015. However, the fact that this is a population-based nationwide study including 9733 patients compensates for some of these limitations.ConclusionsIdentification of patients at increased risk of early death shows that older patients with advanced disease, increased WHO score, primary tumour in the hypopharynx, and those given palliative treatment, are more likely than the others to die from head and neck cancer within six months of diagnosis.