['Carotid blowout syndrome is a severe complication of head and neck cancer. High mortality and major neurologic morbidity are associated with carotid blowout syndrome with massive bleeding. Prediction of outcomes for carotid blowout syndrome patients is important for clinicians, especially for patients with the risk of massive bleeding.', 'Between 1 January 2001 and 31 December 2011, 103 patients with carotid blowout syndrome were enrolled in this study. The patients were divided into groups with and without massive bleeding. Prognostic factors were analysed with proportional hazard (Cox) regressions for carotid blowout syndrome-related prognoses. Survival analyses were based on the time from diagnosis of carotid blowout syndrome to massive bleeding and death.', 'Patients with massive bleeding were more likely to have hypoalbuminemia (albumin <3.5 g/dl; P = 0.023). Univariate analysis of carotid blowout syndrome-related massive bleeding showed that treatment for carotid blowout syndrome (best supportive care, P = 0.000; embolization, P = 0.000), monocytosis (monocytes >1000 cells/μl, P = 0.041) and hypoalbuminemia (P = 0.010) were important to prognosis. Concurrent chemoradiotherapy (P = 0.007), elevated lactate dehydrogenase (>250 U/l; P = 0.050), local recurrence (P = 0.022) and hypoalbuminemia (P = 0.038) were related to poor prognosis in carotid blowout syndrome-related death. In multivariate analysis, best supportive care and hypoalbuminemia were independent factors for both carotid blowout syndrome-related massive bleeding (P = 0.000) and carotid blowout syndrome-related death (P = 0.013), respectively.'] Is serum albumin an important prognostic factor for carotid blowout syndrome?