Although swallowing difficulties have been described in patients with Kearns-Sayre syndrome (KSS), the spectrum of manometric characteristics of dysphagia is not yet well known. Moreover, it is conceivable that a combination of various degrees of swallowing difficulties with different patterns in manometric studies exist, each playing a major role in the prognosis, natural history, and quality of life of KSS patients. An 18-year-old girl diagnosed at the age of 5 years with KSS (muscle biopsy) was admitted to our department with an upper respiratory tract infection and dysphagia. Clinical examination revealed growth retardation, external ophthalmoplegia, pigmentary retinopathy, impaired hearing, and ataxia. An electrocardiogram revealed cardiac conduction defects (long Q-T), and brain magnetic resonance imaging showed abnormalities in the cerebellar hemispheres. A manometric and motility study for dysphagia was conducted and the pharynx and upper esophageal sphincter (UES) resting pressures were similar to control group values, but the swallowing peak contraction pressure of the pharynx and the closing pressure of the UES were very low and could not promote effective peristaltic waves. Relaxation and coordination of the UES were not affected although pharyngeal and upper esophagus peristaltic waves proved to be very low and, consequently, were practically ineffective. The patient was started on treatment comprising a diet rich in potassium, magnesium, and calcium, and oral administration of vitamin D and co-enzyme Q10 100 mg daily; she was discharged 6 days later with apparent clinical improvement.