BACKGROUND: A 59-year-old woman with a history of nodular goiter developed thyrotoxic symptoms while on levothyroxine therapy. Her thyrotoxicosis persisted after levothyroxine withdrawal, so she was given methimazole and, once euthyroid, underwent near-total thyroidectomy. Histological examination revealed a nodular variant of Graves' disease. Proptosis, eyelid swelling and diplopia appeared 2 months after surgery. These symptoms worsened, and the patient was initially given four intravenous pulses of glucocorticoids, which resulted in a transient amelioration of her eye symptoms. After glucocorticoid withdrawal, however, the patient's eye motility worsened and there was a reduction of visual acuity in the left eye. She was then referred to our hospital for further advice and treatment. INVESTIGATIONS: Complete thyroid and ophthalmological evaluation, computerized visual field analysis, CT scan of the orbits, routine blood tests, search for occult fecal blood, blood tests for hepatitis B and C virus markers, measurements of serum non-organ-specific autoantibodies and serum anti-TSH-receptor antibodies, and liver ultrasonography. DIAGNOSIS: Nodular Graves' disease with severe, active Graves' orbitopathy complicated by optic neuropathy. MANAGEMENT: Intravenous glucocorticoid therapy for 3 consecutive days, followed by once-weekly pulses of intravenous glucocorticoids over a 10-week period, and then by oral prednisone treatment on alternate days for 2 months. During the first 2 weeks of intravenous glucocorticoid therapy the patient received orbital irradiation. Therapy resulted in optimized visual acuity and a moderate improvement of soft-tissue inflammatory signs and symptoms, whereas proptosis and eye motility improved only slightly. The patient is now scheduled for orbital decompression and rehabilitative surgery.