AIM: To report an atypical CT scan finding of thyroid eye disease. METHODS: A 64 years old Chinese lady presented with diplopia for 3 months without blurring of vision. She had been diagnosed as thyrotoxicosis with multinodular goitre 14 years back and thyroidectomy was done 14 years ago. Eye examination revealed both eye hypotropia with restricted up gaze movement. There was presence of red desaturation on her left eye with grade I relative afferent pupillary defect. Hormone profile showed normal triiodothyronine (T3), tetraiodothyronine (T4) and thyroid stimulating hormone(TSH). TSH receptor antibody was high which was consistent with Graves’disease. Magnetic resonance imaging(MRI) showed diffused enlargement of both inferior rectus muscle with tendon involvement. RESULTS: Few cycle of intravenous methylprednisolone followed by oral prednisolone were given but left eye vision deteriorated in spite of medical treatment. Left eye orbital decompression was done and her left eye visual acuity was improved after the surgery. CONCLUSION: Extraocular muscle enlargement with tendon involvement does not exclude possibility of thyroid associated orbitopathy (TAO).