OBJECTIVE Follow-up of patients with severe thyroid associated ophthalmopathy treated with a transcranial two-wall orbital decompression and reconstruction. METHODS A two-wall transcranial orbital decompression was performed in 30 such patients (50 eyes). The patients were evaluated one month postoperatively, and long-term evaluation (median 14 months, range 2-54 months) was carried out. The main outcome measures were visual acuity, proptosis measured by Hertel ophthalmometry, soft tissue involvement, and restriction of eye motility. RESULTS Visual acuity improved rapidly in 28 of 32 affected eyes with normalization in 19 eyes (p<0.001). Worsening was not seen. Median proptosis was reduced by 4.0 mm, range 0-10.0 (p<0.001). Double vision was present in 24 patients before operation 14 of whom achieved binocular vision (p<0.001). Three patients had unchanged complaints and the double vision worsened in one patient. Seventeen of 20 patients on preoperative corticosteroid treatment discontinued this medication in relation to surgery. Complications included one case of perioperative minor stroke and two cases of facial nerve frontal branch palsy. CONCLUSIONS The transcranial two-wall decompression is a simple, an efficient and a low-risk procedure for treatment of patients with severe thyroid associated ophthalmopathy.