Internal jugular vein thrombosis is an uncommon potentially life-threatening disorder caused by various conditions. Non-spontaneous internal jugular vein thrombosis is an uncommon condition associated in the preantibiotic area with deep-neck infections. Currently iatrogenic trauma to the internal jugular vein from catheterisation and repeated intravenous injections by drug abusers are the leading causes of thrombosis. Spontaneous internal jugular vein thrombosis may occur when there are no apparent pre-disposing mechanical or inflammatory causes although a few of these patients may harbour an occult malignant neoplasm. Hence, careful investigation and follow-up are vital. Thrombosis in Trousseau's syndrome is usually confined to the vascular system of the extremities and the viscera. However, secondary to the paraneoplastic hypercoagulable state, thrombosis can occur in the large veins of the head and neck region. We understand this to be the first case where spontaneous internal jugular vein thrombosis and ipsilateral recurrent laryngeal nerve paralysis were the only initial manifestations of an occult malignancy.