In 1950 H. W. Brown reported the superior oblique tendon sheath syndrome and cut the sheath as treatment for the condition. My results (as well as those of other surgeons) with similar surgery have been disappointing. Consequently, I carried out different operations consisting of Z tenotomy of superior oblique tendon in nine patients, split tendon lengthening in two patients, complete tenotomy in 16 patients, and a tenectomy in two patients. One of the latter was done on a patient after an unsatisfactory tenotomy where I missed the tendon. Tenotomy of the superior oblique tendon gave the best results. Experiments with the superior oblique tendon in cadavers several hours after death showed that after cutting the tendon just medial to the superior rectus muscle, the cut end of the tendon moved medially only about 8 to 10 mm due to restrictions of the capsular attachments to the trochlea. The cause of "true" Brown's syndrome is a tight tendon, and a safe and effective surgical treatment consists of cutting it just medial to the superior rectus muscle.