Objective: West Nile virus has recently become a public health concern in the United States, after an outbreak in New York City in 1999. It is a mosquito-borne virus that causes a spectrum of disease from flu-like symptoms to encephalopathy, muscle weakness, and, in some cases, death.

Study Design: Case Report.

Methods: A patient infected with West Nile virus presented with progressive muscle weakness, and later developed bilateral vocal fold paresis. His clinical presentation, physical and laboratory examination findings, and course of illness will be discussed.

Results: After a prolonged hospital stay, and presumptive treatment for Guillain-Barré, repeat CSF analysis revealed infection with the West Nile virus. The patient developed bilateral vocal fold paralysis during his hospital course. At long-term follow-up, the patient's left vocal fold paralysis persisted, while the right vocal fold paralysis had resolved.

Conclusions: Although several viruses have been associated with recurrent laryngeal nerve injury, this is the first report of West Nile virus induced vocal fold paralysis.