Direct tumour extension into the internal jugular veins (IJV) and right atrium in thyroid cancer is extremely uncommon. We report three cases of advanced thyroid cancer invading into the IJV and right atrium. All three patients had well-differentiated thyroid cancer and presented with typical clinical picture of the superior cava syndrome coupled with significant compressive symptoms. Two patients had obvious tumour thrombus extending to the superior vena cava (SVC) and right atrium, whilst in one patient, the thrombus extended to the SVC close to the edge of the right atrium. In all three patients, the intraluminal tumour thrombus was clinically palpable. Involvement of the IJV, SVC and right atrium was confirmed with computed tomography (CT) scan and echocardiography. The decision to extract the thrombus transcervically was made on the basis of the positive "ring sign", which is a thin rim of contrast surrounding the tumour thrombus documented on CT. All three patients underwent total thyroidectomy with segmental resection and ligation of the IJV. The tumour thrombus was successfully extracted transcervically. The histopathology report confirmed follicular carcinoma in all three patients. Two patients had radioiodine ablation therapy postoperatively, and were well 18 months after operation. One patient who had lung metastases documented on chest CT succumbed to the disease due to massive haemoptysis 3 weeks after operation.