AbstractBackground:Carotid blow-out syndrome is one of the most devastating complications of head and neck carcinoma. It usually occurs as a post-operative complication or when the tumour compromises the vascular axis.Methods and results:We report two patients who suffered carotid blow-out syndrome but who did not have the usual predisposing factors. Both patients had a pharyngolaryngeal carcinoma that was treated with chemoradiotherapy. Residual non-tumoural ulceration was seen along the lateral wall of the hypopharynx in both cases. This ulceration eventually reached the vascular axis, precipitating carotid rupture and death.Conclusion:Residual non-tumoural ulceration of the lateral wall of the hypopharynx after chemoradiotherapy should be considered with the utmost caution. Once persistence of the tumour is excluded, surgery is indicated to protect the vascular axis, in order to prevent carotid blow-out syndrome.