Fluorescein fundus cinematography was employed to study the circulatory alterations produced in owl monkeys by intracarotid injection of air. The studies reported herein demonstrate a marked but variable reduction in blood flow in various sectors of the eye, presumably due to interruption of the viscous blood column with air bubbles. Apparently dependent upon the volume of the air embolism, obstruction may be total to a major arterial branch or detected only by slowing of the dye circulation. Occasionally, the air bolus may progress through the system, leaving a trace of intense leakage of fluorescein dye, which is taken as an indicator of endothelial damage.