Purpose. Collet-Sicard syndrome is a very rare condition characterised by unilateral palsy of the IX-XII cranial nerves. It is distinguished from Villaret syndrome by lack of presence of sympathetic involvement. Current literature contains only two cases of Collet-Sicard syndrome due to idiopathic internal jugular vein thrombosis. Method and Results. We report the case of Collet-Sicard syndrome in a 30-year-old man who presented with delayed development of XIth nerve dysfunction, due to internal jugular vein-sigmoid sinus thrombosis. A multidisciplinary team approach was employed in the management of this patient. At three-month followup, he had significantly improved swallowing, and repeat computed tomography neck scan showed partial recanalisation of the right internal jugular vein. Conclusion. In suspected Collet-Sicard syndrome, a focal primary lesion or metastasis to the temporal bone must be excluded, and sigmoid-jugular complex thrombosis should be considered in the differential diagnosis. Early recognition and treatment may result in significant functional recovery.