Extensive retropharyngeal haemorrhage is a rare event, which is occasionally encountered in clinical practice, but very seldom at autopsy. A 43-year-old woman who presented with difficulty breathing after a week's history of sore throat and coughing is reported. She collapsed at a medical centre and was not able to be resuscitated. Staff noted that she had 'swelling' of her throat. At autopsy, the major findings were in the anterior neck where there was extensive and diffuse retropharyngeal haemorrhage extending throughout the soft tissue planes resulting in marked stenosis of the laryngeal inlet. There was no evidence of external or internal trauma, and although no specific source of the retropharyngeal haemorrhage was identified, the haemorrhage clearly originated from the retropharyngeal space with diffuse extension Her past medical history included anticoagulation for atrial fibrillation and heart valve replacements, hepatic steatosis and sleep apnoea. This case demonstrates a significant complication of oral anticoagulation therapy with underlying comorbidities which may result in significant neck haemorrhage with critical upper airway narrowing and rapid clinical deterioration.