The internal jugular vein is an uncommon site of spontaneous venous thrombosis. Most cases usually result from intravenous drug abuse, jugular vein catheterisation, neck dissection, a hypercoagulable state associated with malignancy (Trousseau's syndrome), neck injury or ovarian overstimulation syndrome. In this paper, we present and discuss two cases of spontaneous jugular vein thrombosis associated with breast and lung malignancies. The possibility of Trousseau's syndrome due to distant malignancy should be considered by otolaryngologists and appropriately investigated.