In rare cases, unilateral jugular vein thrombosis can lead to increased intracranial pressure and papilloedema, resulting in headaches and visual loss. The authors describe the case of a 45-year-old patient with squamous cell carcinoma of the larynx who developed right jugular vein thrombosis following chemoradiation therapy. The patient later went on to develop the complications of intracranial hypertension and papilloedema. The authors discuss the normal cerebral venous drainage, the potential role of chemoradiation therapy on the aetiology of jugular vein thrombosis and the mechanism of increased intracranial pressure secondary to unilateral jugular vein occlusion. This case highlights the need to consider increased intracranial pressure as a diagnosis in a patient presenting with headache and papilloedema, even if the papilloedema is only unilateral and one jugular vein is still patent. A prompt diagnosis and treatment can have a positive impact on the visual outcome.