In 40 cases of acquired superior oblique palsy, head trauma was the most frequent cause. The pattern of the resulting vertical, horizontal, and torsional defects is discussed. Data are presented, indicating that the habitual head tilt is a compensation to reduce the vertical deviation, and thus aid fusion. In surgical treatment, weakening of the antagonist inferior oblique muscle will often be required. Vertical rectus muscle surgery in addition to inferior oblique muscle surgery is required if the vertical deviation exceeds 15 to 20 prism diopters in the primary position. Horizontal muscle surgery is required if inferior oblique weakening is to be done in cases with esodeviation over 4 to 5 Δ in the primary position. Tucking of the paretic superior oblique is found to be of less value than inferior oblique and vertical rectus muscle surgery.