Thyroid-related orbitopathy (TRO) is considered to be an inflammatory autoimmune disorder that commonly presents with extraocular muscle and retrobulbar fat enlargement. Lacrimal gland enlargement in TRO has been reported in the past in association with other radiological findings. Our case represents an isolated lacrimal gland enlargement as a presenting radiological finding in an euthyroid patient showing elevation of thyroid-stimulating immunoglobulin. After ruling out possible pathologies such as a monoclonal process, lacrimal epithelial tumor, or a nonspecific orbital inflammation, the patient underwent orbital decompression, serial botulinum toxin injections, and upper eyelid-retraction surgical correction. After two years of follow-up, the patient developed new-onset diplopia; consequent imaging showed extraocular muscle enlargement which was not present on previous imaging.