Graves' orbitopathy can be associated with horizontal, vertical, and torsional diplopia. Of 428 patients treated with transantral orbital decompression, 21 had incycloduction (mean, 12.8 degrees; range, 5 to 20 degrees) and five had excycloduction (mean, 12 degrees; range, 5 to 20 degrees). All 26 patients had had recessions of the medial or inferior rectus muscle (or both) before onset of torsional diplopia. Mean recession was 5.5 mm (range, 4 to 10 mm) and 5.3 mm (range, 2 to 10 mm) of medial rectus muscle and inferior rectus muscle, respectively. An A pattern was often associated with the condition. Superior oblique tenectomy and inferior oblique myectomy were performed most frequently for incycloduction and excycloduction, respectively. Superior oblique tenectomy induced a mean incycloduction decrease of 7.1 degrees (range, 0 to 12 degrees). Exotropia in downgaze was decreased, and a small ipsilateral hyperdeviation was induced. Bilateral inferior oblique myectomy in one patient decreased excycloduction 10 degrees without inducing new deviation. At follow-up (mean, 63.7 months) after last strabismus operation, 15 patients with incycloduction and two with excycloduction had no diplopia.