Cosmetic blepharoplasty is the most often performed procedure in plastic surgery and ophthalmic plastic surgery. Many complications have been reported including ectropion, exposure keratitis, hemorrhage, epiphora, infection, vision loss, and, very rarely, diplopia. Although uncommon, there have been several case reports and case series published evaluating possible causes of this problem, including aggressive excision of fat, wound-related inflammation, conjunctival edema, and temporary muscle disturbances. Although the inferior oblique muscle is most susceptible to injury, the inferior rectus and superior oblique muscles are also subject to trauma. When performing cosmetic blepharoplasties, surgeons should be cautious when dissecting fat pads and should do so under direct visualization. Meticulous cautery is also important to avoiding injury to the extraocular muscles. Fresnel prisms and Bangerter filters can be used to help alleviate diplopia in patients with small-angle strabismus. Surgical exploration and extraocular muscle surgery may be indicated in patients with diplopia that cannot be resolved with nonsurgical treatment.