Kearns-Sayre syndrome is a rare disorder caused by mitochondrial deoxyribonucleic acid deletion. It is characterized by a triad of progressive external ophthalmoplegia, initial symptoms that develop before the age of 20 years, and pigmentary retinopathy. Multisystem involvement is frequently associated with those features. Ragged red fibers can be identified during histopathologic examination and confirmed by electron microscopy. In this article, the case of a 38-year-old mail with Keams-Sayre syndrome in whom diagnosis was delayed despite abundant clinical evidence is presented. A brief review of clinical and laboratory findings in patients with that disorder is also provided.