Medial rectus injury is an uncommon but often devastating complication of functional endoscopic sinus surgery. Prevention of these types of injuries is predicated on a thorough preoperative assessment of the position and integrity of the medial orbital wall coupled with excellent surgical technique. The use of powered instrumentation has led to more severe injuries and thus should be used with caution near critical structures such as the lamina papyracea. Early recognition and management of medial rectus and associated orbital injuries is critical to improve outcomes and prevent associated complications. Despite optimal surgical and medical interventions, the prognosis is relatively poor and patients should be counseled that the primary goal of these interventions is to reestablish a binocular single visual field.